Posts Tagged: ransomware


5
Sep 17

Who Is Marcus Hutchins?

In early August 2017, FBI agents in Las Vegas arrested 23-year-old British security researcher Marcus Hutchins on suspicion of authoring and/or selling “Kronos,” a strain of malware designed to steal online banking credentials. Hutchins was virtually unknown to most in the security community until May 2017 when the U.K. media revealed him as the “accidental hero” who inadvertently halted the global spread of WannaCry, a ransomware contagion that had taken the world by storm just days before.

Relatively few knew it before his arrest, but Hutchins has for many years authored the popular cybersecurity blog MalwareTech. When this fact became more widely known — combined with his hero status for halting Wannacry — a great many MalwareTech readers quickly leapt to his defense to denounce his arrest. They reasoned that the government’s case was built on flimsy and scant evidence, noting that Hutchins has worked tirelessly to expose cybercriminals and their malicious tools. To date, some 226 supporters have donated more than $14,000 to his defense fund.

Marcus Hutchins, just after he was revealed as the security expert who stopped the WannaCry worm. Image: twitter.com/malwaretechblog

Marcus Hutchins, just after he was revealed as the security expert who stopped the WannaCry worm. Image: twitter.com/malwaretechblog

At first, I did not believe the charges against Hutchins would hold up under scrutiny. But as I began to dig deeper into the history tied to dozens of hacker forum pseudonyms, email addresses and domains he apparently used over the past decade, a very different picture began to emerge.

In this post, I will attempt to describe and illustrate more than three weeks’ worth of connecting the dots from what appear to be Hutchins’ earliest hacker forum accounts to his real-life identity. The clues suggest that Hutchins began developing and selling malware in his mid-teens — only to later develop a change of heart and earnestly endeavor to leave that part of his life squarely in the rearview mirror.

GH0STHOSTING/IARKEY

I began this investigation with a simple search of domain name registration records at domaintools.com [full disclosure: Domain Tools recently was an advertiser on this site]. A search for “Marcus Hutchins” turned up a half dozen domains registered to a U.K. resident by the same name who supplied the email address “surfallday2day@hotmail.co.uk.”

One of those domains — Gh0sthosting[dot]com (the third character in that domain is a zero) — corresponds to a hosting service that was advertised and sold circa 2009-2010 on Hackforums[dot]net, a massively popular forum overrun with young, impressionable men who desperately wish to be elite coders or hackers (or at least recognized as such by their peers).

The surfallday2day@hotmail.co.uk address tied to Gh0sthosting’s initial domain registration records also was used to register a Skype account named Iarkey that listed its alias as “Marcus.” A Twitter account registered in 2009 under the nickname “Iarkey” points to Gh0sthosting[dot]com.

Gh0sthosting was sold by a Hackforums user who used the same Iarkey nickname, and in 2009 Iarkey told fellow Hackforums users in a sales thread for his business that Gh0sthosting was “mainly for blackhats wanting to phish.” In a separate post just a few days apart from that sales thread, Iarkey responds that he is “only 15” years old, and in another he confirms that his email address is surfallday2day@hotmail.co.uk.

daloseronly15

A review of the historic reputation tied to the Gh0sthosting domain suggests that at least some customers took Iarkey up on his offer: Malwaredomainlist.com, for example, shows that around this same time in 2009 Gh0sthosting was observed hosting plenty of malware, including trojan horse programs, phishing pages and malware exploits.

A “reverse WHOIS” search at Domaintools.com shows that Iarkey’s surfallday2day email address was used initially to register several other domains, including uploadwith[dot]us and thecodebases[dot]com.

Shortly after registering Gh0sthosting and other domains tied to his surfallday2day@hotmail.co.uk address, Iarkey evidently thought better of including his real name and email address in his domain name registration records. Thecodebases[dot]com, for example, changed its WHOIS ownership to a “James Green” in the U.K., and switched the email to “herpderpderp2@hotmail.co.uk.”

A reverse WHOIS lookup at domaintools.com for that email address shows it was used to register a Hackforums parody (or phishing?) site called Heckforums[dot]net. The domain records showed this address was tied to a Hackforums clique called “Atthackers.” The records also listed a Michael Chanata from Florida as the owner. We’ll come back to Michael Chanata and Atthackers at the end of this post. Continue reading →


27
Jun 17

‘Petya’ Ransomware Outbreak Goes Global

A new strain of ransomware dubbed “Petya” is worming its way around the world with alarming speed. The malware is spreading using a vulnerability in Microsoft Windows that the software giant patched in March 2017 — the same bug that was exploited by the recent and prolific WannaCry ransomware strain.

The ransom note that gets displayed on screens of Microsoft Windows computers infected with Petya.

The ransom note that gets displayed on screens of Microsoft Windows computers infected with Petya.

According to multiple news reports, Ukraine appears to be among the hardest hit by Petya. The country’s government, some domestic banks and largest power companies all warned today that they were dealing with fallout from Petya infections.

Danish transport and energy firm Maersk said in a statement on its Web site that “We can confirm that Maersk IT systems are down across multiple sites and business units due to a cyber attack.” In addition, Russian energy giant Rosneft said on Twitter that it was facing a “powerful hacker attack.” However, neither company referenced ransomware or Petya.

Security firm Symantec confirmed that Petya uses the “Eternal Blue” exploit, a digital weapon that was believed to have been developed by the U.S. National Security Agency and in April 2017 leaked online by a hacker group calling itself the Shadow Brokers.

Microsoft released a patch for the Eternal Blue exploit in March (MS17-010), but many businesses put off installing the fix. Many of those that procrastinated were hit with the WannaCry ransomware attacks in May. U.S. intelligence agencies assess with medium confidence that WannaCry was the work of North Korean hackers.

Organizations and individuals who have not yet applied the Windows update for the Eternal Blue exploit should patch now. However, there are indications that Petya may have other tricks up its sleeve to spread inside of large networks. Continue reading →


23
Jun 17

FBI: Extortion, CEO Fraud Among Top Online Fraud Complaints in 2016

Online extortion, tech support scams and phishing attacks that spoof the boss were among the most costly cyber scams reported by consumers and businesses last year, according to new figures from the FBI’s Internet Crime Complaint Center (IC3).

The IC3 report released Thursday correctly identifies some of the most prevalent and insidious forms of cybercrimes today, but the total financial losses tied to each crime type also underscore how infrequently victims actually report such crimes to law enforcement.

Source: Internet Crime Complaint Center (IC3).

Source: Internet Crime Complaint Center (IC3).

For example, the IC3 said it received 17,146 extortion-related complaints, with an adjusted financial loss totaling just over $15 million. In that category, the report identified 2,673 complaints identified as ransomware — malicious software that scrambles a victim’s most important files and holds them hostage unless and until the victim pays a ransom (usually in a virtual currency like Bitcoin).

According to the IC3, the losses associated with those ransomware complaints totaled slightly more than $2.4 million. Writing for BleepingComputer.com — a tech support forum I’ve long recommended that helps countless ransomware victims — Catalin Cimpanu observes that the FBI’s ransomware numbers “are ridiculously small compared to what happens in the real world, where ransomware is one of today’s most prevalent cyber-threats.”

“The only explanation is that people are paying ransoms, restoring from backups, or reinstalling PCs without filing a complaint with authorities,” Cimpanu writes.

It’s difficult to know how what percentage of ransomware victims paid the ransom or were able to restore from backups, but one thing is for sure: Relatively few victims are reporting cyber fraud to federal investigators.

The report notes that only an estimated 15 percent of the nation’s fraud victims report their crimes to law enforcement. For 2016, 298,728 complaints were received, with a total victim loss of $1.33 billion.

If that 15 percent estimate is close to accurate, that means the real cost of cyber fraud for Americans last year was probably closer to $9 billion, and the losses from ransomware attacks upwards of $16 million. Continue reading →


29
Dec 16

Happy Seventh Birthday, KrebsOnSecurity!

Hard to believe it’s time to celebrate another go ’round the Sun for KrebsOnSecurity! Today marks exactly seven years since I left The Washington Post and started this here solo thing. And what a remarkable year 2016 has been!

7-2016

The word cloud above includes a sampling of tags used in stories on KrebsOnSecurity throughout the past year. It’s been a wild one, riddled with huge attacks, big cybercriminal busts and of course a whole mess of data breaches.

The biggest attack of all — the 620 Gbps distributed denial-of-service (DDoS) assault against this site on Sept. 22 — resulted in KrebsOnSecurity being unplugged for several days. The silver lining? I now have a stronger site and readership. Through it all, the community that has grown up around this site was extremely supportive and encouraging. I couldn’t be prouder of this community, so a huge THANK YOU to all of my readers, both new and old.

It’s fair to say that many of the subjects in the word cloud above are going to continue to haunt us in 2017, particularly ransomware, CEO fraud and DDoS attacks. I am hopeful to have more on the “who” behind the September attacks against this site in the New Year. I promise it’s going to be a story worth waiting for. Stay tuned. Continue reading →


22
Dec 16

Before You Pay that Ransomware Demand…

A decade ago, if a desktop computer got infected with malware the chief symptom probably was an intrusive browser toolbar of some kind. Five years ago you were more likely to get whacked by a banking trojan that stole all your passwords and credit card numbers. These days if your mobile or desktop computer is infected what gets installed is likely to be “ransomware” — malicious software that locks your most prized documents, songs and pictures with strong encryption and then requires you to pay for a key to unlock the files.

Here’s some basic advice about where to go, what to do — and what not to do — when you or someone you know gets hit with ransomware.

Image: nomoreransom.org

Image: nomoreransom.org

First off — breathe deep and try not to panic. And don’t pay the ransom.

True, this may be easier said than done: In many cases the ransom note that hijacks the victim’s screen is accompanied by a digital clock ominously ticking down the minutes and seconds from 72 hours. When the timer expires, the ransom demand usually goes up or even doubles. Continue to ignore the demands and your files will be gone, kaput, nil, nyet, zilch, done forever, warns the extortion message.

See, the key objective of ransomware is a psychological one — to instill fear, uncertainty and dread in the victim — and to sow the conclusion in the victim’s mind that any solution for restoring full access to all his files involves paying up. Indeed, paying the ransom is often the easiest, fastest and most complete way of reversing a security mistake, such as failing to patch, opening a random emailed document e.g., or clicking a link that showed up unbidden in instant message. Some of the more advanced and professional ransomware operations have included helpful 24/7 web-based tech support.

The ransom note from a recent version of the "Locky" ransomware variant. Image: Bleepingcomputer.com.

The ransom note from a recent version of the “Locky” ransomware variant. Image: Bleepingcomputer.com.

Paying up is certainly not the cheapest option. The average ransom demanded is approximately $722, according to an analysis published in September by Trend Micro. Interestingly, Trend found the majority of organizations that get infected by ransomware end up paying the ransom. They also found three-quarters of companies which had not suffered a ransomware infection reported they would not pay up when presented with a data ransom demand. Clearly, people tend to see things differently when they’re the ones in the hot seat.

And for those not yet quite confident in the ways of Bitcoin (i.e. most victims), paying up means a crash course in acquiring the virtual currency known as Bitcoin. Some ransomware attackers are friendlier than others in helping victims wade through the process of setting up an account to handle Bitcoin, getting it funded, and figuring out how to pay other people with it. Others just let you figure it all out. The entire ordeal is a trial by fire for sure, but it can also be a very expensive, humbling and aggravating experience.

In the end the extortionist may bargain with you if they’re in a good mood, or if you have a great sob story. But they still want you to know that your choice is a binary one: Pay up, or kiss your sweet files goodbye forever.

This scenario reminds me of the classic short play/silent movie about the villainous landlord and the poor young lady who can’t pay the rent. I imagine the modern version of this play might go something like…

mustpaytherentVillain: You MUST pay the ransom!

Victim: I CAN’T pay the ransom!

Villain: You MUST pay the ransom!

Victim: I CAN’T pay the ransom!

Hero: I’ll pay the ransom!

Victim: Oh! My hero!

Villain: Curses! Foiled again!

Okay, nobody’s going to pay the ransomware demand for you (that’s only in Hollywood!). But just like the hero in the silent movie, there are quite a few people out there who are in fact working hard to help victims avoid paying the ransom (AND get their files back to boot).

Assuming you don’t have a recent backup you can restore, fear not: With at least some strains of ransomware, the good guys have already worked out a way to break or sidestep the encryption, and they’ve posted the keys needed to unlock these malware variants free of charge online.

But is the strain that hit your device one that experts already know how to crack?  Continue reading →


29
Nov 16

San Francisco Rail System Hacker Hacked

The San Francisco Municipal Transportation Agency (SFMTA) was hit with a ransomware attack on Friday, causing fare station terminals to carry the message, “You are Hacked. ALL Data Encrypted.” Turns out, the miscreant behind this extortion attempt got hacked himself this past weekend, revealing details about other victims as well as tantalizing clues about his identity and location.

A copy of the ransom message left behind by the "Mamba" ransomware.

A copy of the ransom message left behind by the “Mamba” ransomware.

On Friday, The San Francisco Examiner reported that riders of SFMTA’s Municipal Rail or “Muni” system were greeted with handmade “Out of Service” and “Metro Free” signs on station ticket machines. The computer terminals at all Muni locations carried the “hacked” message: “Contact for key (cryptom27@yandex.com),” the message read.

The hacker in control of that email account said he had compromised thousands of computers at the SFMTA, scrambling the files on those systems with strong encryption. The files encrypted by his ransomware, he said, could only be decrypted with a special digital key, and that key would cost 100 Bitcoins, or approximately USD $73,000.

On Monday, KrebsOnSecurity was contacted by a security researcher who said he hacked this very same cryptom27@yandex.com inbox after reading a news article about the SFMTA incident. The researcher, who has asked to remain anonymous, said he compromised the extortionist’s inbox by guessing the answer to his secret question, which then allowed him to reset the attacker’s email password. A screen shot of the user profile page for cryptom27@yandex.com shows that it was tied to a backup email address, cryptom2016@yandex.com, which also was protected by the same secret question and answer.

Copies of messages shared with this author from those inboxes indicate that on Friday evening, Nov. 25, the attacker sent a message to SFMTA infrastructure manager Sean Cunningham with the following demand (the entirety of which has been trimmed for space reasons), signed with the pseudonym “Andy Saolis.”

“if You are Responsible in MUNI-RAILWAY !

All Your Computer’s/Server’s in MUNI-RAILWAY Domain Encrypted By AES 2048Bit!

We have 2000 Decryption Key !

Send 100BTC to My Bitcoin Wallet , then We Send you Decryption key For Your All Server’s HDD!!”

One hundred Bitcoins may seem like a lot, but it’s apparently not far from a usual payday for this attacker. On Nov. 20, hacked emails show that he successfully extorted 63 bitcoins (~$45,000) from a U.S.-based manufacturing firm.

The attacker appears to be in the habit of switching Bitcoin wallets randomly every few days or weeks. “For security reasons” he explained to some victims who took several days to decide whether to pay the ransom they’d been demanded. A review of more than a dozen Bitcoin wallets this criminal has used since August indicates that he has successfully extorted at least $140,000 in Bitcoin from victim organizations.

That is almost certainly a conservative estimate of his overall earnings these past few months: My source said he was unable to hack another Yandex inbox used by this attacker between August and October 2016, “w889901665@yandex.com,” and that this email address is tied to many search results for tech help forum postings from people victimized by a strain of ransomware known as Mamba and HDD Cryptor.

Copies of messages shared with this author answer many questions raised by news media coverage of this attack, such as whether the SFMTA was targeted. In short: No. Here’s why.

Messages sent to the attacker’s cryptom2016@yandex.com account show a financial relationship with at least two different hosting providers. The credentials needed to manage one of those servers were also included in the attacker’s inbox in plain text, and my source shared multiple files from that server.

KrebsOnSecurity sought assistance from several security experts in making sense of the data shared by my source. Alex Holden, chief information security officer at Hold Security Inc, said the attack server appears to have been used as a staging ground to compromise new systems, and was equipped with several open-source tools to help find and infect new victims.

“It appears our attacker has been using a number of tools which enabled the scanning of large portions of the Internet and several specific targets for vulnerabilities,” Holden said. “The most common vulnerability used ‘weblogic unserialize exploit’ and especially targeted Oracle Corp. server products, including Primavera project portfolio management software.”

According to a review of email messages from the Cryptom27 accounts shared by my source, the attacker routinely offered to help victims secure their systems from other hackers for a small number of extra Bitcoins. In one case, a victim that had just forked over a 20 Bitcoin ransom seemed all too eager to pay more for tips on how to plug the security holes that got him hacked. In return, the hacker pasted a link to a Web server, and urged the victim to install a critical security patch for the company’s Java applications.

“Read this and install patch before you connect your server to internet again,” the attacker wrote, linking to this advisory that Oracle issued for a security hole that it plugged in November 2015.

In many cases, the extortionist told victims their data would be gone forever if they didn’t pay the ransom in 48 hours or less. In other instances, he threatens to increase the ransom demand with each passing day. Continue reading →


15
Sep 16

Ransomware Getting More Targeted, Expensive

I shared a meal not long ago with a source who works at a financial services company. The subject of ransomware came up and he told me that a server in his company had recently been infected with a particularly nasty strain that spread to several systems before the outbreak was quarantined. He said the folks in finance didn’t bat an eyelash when asked to authorize several payments of $600 to satisfy the Bitcoin ransom demanded by the intruders: After all, my source confessed, the data on one of the infected systems was worth millions — possibly tens of millions — of dollars, but for whatever reason the company didn’t have backups of it.

This anecdote has haunted me because it speaks volumes about what we can likely expect in the very near future from ransomware — malicious software that scrambles all files on an infected computer with strong encryption, and then requires payment from the victim to recover them.

Image: Kaspersky Lab

What we can expect is not only more targeted and destructive attacks, but also ransom demands that vary based on the attacker’s estimation of the value of the data being held hostage and/or the ability of the victim to pay some approximation of what it might be worth.

In an alert published today, the U.S. Federal Bureau of Investigation (FBI) warned that recent ransomware variants have targeted and compromised vulnerable business servers (rather than individual users) to identify and target hosts, thereby multiplying the number of potential infected servers and devices on a network.

“Actors engaging in this targeting strategy are also charging ransoms based on the number of host (or servers) infected,” the FBI warned. “Additionally, recent victims who have been infected with these types of ransomware variants have not been provided the decryption keys for all their files after paying the ransom, and some have been extorted for even more money after payment.”

According to the FBI, this recent technique of targeting host servers and systems “could translate into victims paying more to get their decryption keys, a prolonged recovery time, and the possibility that victims will not obtain full decryption of their files.”

fbipsi-ransom

Today there are dozens of ransomware strains, most of which are sold on underground forums as crimeware packages — with new families emerging regularly. These kits typically include a point-and-click software interface for selecting various options that the ransom installer may employ, as well as instructions that tell the malware where to direct the victim to pay the ransom. Some kits even bundle the HTML code needed to set up the Web site that users will need to visit to pay and recover their files.

To some degree, a variance in ransom demands based on the victim’s perceived relative wealth is already at work. Lawrence Abrams, owner of the tech-help site BleepingComputer, said his analysis of multiple ransomware kits and control channels that were compromised by security professionals indicate that these kits usually include default suggested ransom amounts that vary depending on the geographic location of the victim.

“People behind these scams seem to be setting different rates for different countries,” Abrams said. “Victims in the U.S. generally pay more than people in, say, Spain. There was one [kit] we looked at recently that showed while victims in the U.S. were charged $200 in Bitcoin, victims in Italy were asked for just $20 worth of Bitcoin by default.”

In early 2016, a new ransomware variant dubbed “Samsam” (PDF) was observed targeting businesses running outdated versions of Red Hat‘s JBoss enterprise products. When companies were hacked and infected with Samsam, Abrams said, they received custom ransom notes with varying ransom demands.

“When these companies were hacked, they each got custom notes with very different ransom demands that were much higher than the usual amount,” Abrams said. “These were very targeted.”

Which brings up the other coming shift with ransomware: More targeted ransom attacks. For the time being, most ransomware incursions are instead the result of opportunistic malware infections. The first common distribution method is spamming the ransomware installer out to millions of email addresses, disguising it as a legitimate file such as an invoice.

More well-heeled attackers may instead or also choose to spread ransomware using “exploit kits,” a separate crimeware-as-a-service product that is stitched into hacked or malicious Web sites and lying in wait for someone to visit with a browser that is not up to date with the latest security patches (either for the browser itself or for a myriad of browser plugins like Adobe Flash or Adobe Reader).

But Abrams said that’s bound to change, and that the more targeted attacks are likely to come from individual hackers who can’t afford to spend thousands of dollars a month renting exploit kits.

“If you throw your malware into a good exploit kit, you can achieve a fairly wide distribution of it in a short amount of time,” Abrams said. “The only problem is the good kits are very expensive and can cost upwards of $4,000 per month. Right now, most of these guys are just throwing the ransomware up in the air and wherever it lands is who they’re targeting. But that’s going to change, and these guys are going to start more aggressively targeting really data intensive organizations like medical practices and law and architectural firms.”

Earlier this year, experts began noticing that ransomware purveyors appeared to be targeting hospitals — organizations that are extremely data-intensive and heavily reliant on instant access to patient records. Indeed, the above-mentioned SamSAM ransomware family is thought to be targeting healthcare firms.

According to a new report by Intel Security, the healthcare sector is experiencing over 20 data loss incidents per day related to ransomware attacks. The company said it identified almost $100,000 in payments from hospital ransomware victims to specific bitcoin accounts so far in 2016. Continue reading →


14
Jan 16

Ransomware a Threat to Cloud Services, Too

Ransomware — malicious software that encrypts the victim’s files and holds them hostage unless and until the victim pays a ransom in Bitcoin — has emerged as a potent and increasingly common threat online. But many Internet users are unaware that ransomware also can just as easily seize control over files stored on cloud services.

ransomhandToni Casala found this out the hard way. Casala’s firm — Children in Film — works as an advocate for young actors and their families. The company’s entire operations run off of application hosting services at a managed cloud solutions firm in California, from QuickBooks to Microsoft Office and Outlook. Employees use Citrix to connect to the cloud, and the hosting firm’s application maps the cloud drive as a local disk on the user’s hard drive.

“We were loving that situation,” Casala said. “We can keep the computers here at work empty, and the service is very inexpensive when you compare it the cost of having more IT people on staff. Also, when we need support, they are very responsive. We don’t get farmed out to some call center in India.”

They were loving it, that is, until just before New Year’s Eve, when an employee opened an email attachment that appeared to be an invoice. Thirty minutes later, nobody in Casala’s firm could access any of the company’s 4,000+ files stored on the cloud drive.

“Someone in my office was logged into Outlook and opened up invoice attachment and BAM!, within 30 minutes, every single file on our Q drive had ‘vvv’ added as file extensions,” she said. Every single folder -had a file that said “help.decrypt,” essentially the attacker’s’ instructions for how to pay the ransom.

The cloud provider that Casala’s company is using was keeping daily backups, but she said it still took them almost a week to fully restore all of the files that were held hostage. She said the hosting service told her that the malware also disrupted operations for other customers on the same server.

Casala said her company got lucky on several fronts. For starters, the infection happened right before her firm closed down operations for the New Year’s break, so the outage was less of a disruption than it might normally have been.

More importantly, the malware that scrambled their files — a strain of ransomware called TeslaCrypt, contained a coding weakness that has allowed security and antivirus firms to help victims decrypt the files without paying the ransom. Users over at the computer help forum BleepingComputer have created TeslaDecoder, which allows victims to decrypt files locked by TeslaCrypt.

Casala said the hosting firm had antivirus installed on the server, but that the ransomware slipped past those defenses. That’s because the crooks who are distributing ransomware engineer the malware to evade detection by antivirus software. For more on how cybercriminals achieve that, see Antivirus is Dead: Long Live Antivirus.

The best defense against ransomware is a good set of data backups that are made each day — preferably to a device that is not always connected to the network. Unfortunately, this is often easier said than done, especially for small businesses. For many ransomware victims who do not have backups to rely upon, the choice of whether to pay comes down to the question of how badly the victim needs access to the ransomed files, and whether the files lost are worth more than the ransom demand (which is usually only a few hundred dollars in Bitcoin). Continue reading →


6
Nov 13

CryptoLocker Crew Ratchets Up the Ransom

Last week’s article about how to prevent CryptoLocker ransomware attacks generated quite a bit of feedback and lots of questions from readers. For some answers — and since the malware itself has morphed significantly in just a few day’s time — I turned to Lawrence Abrams and his online help forum BleepingComputer.com, which have been following and warning about this scourge for several months.

This message is left by CryptoLocker for victims whose antivirus software removed the file needed to pay the ransom.

This message is left by CryptoLocker for victims whose antivirus software removes the file needed to pay the ransom.

To recap, CryptoLocker is a diabolical new twist on an old scam. The malware encrypts all of the most important files on a victim PC — pictures, movie and music files, documents, etc. — as well as any files on attached or networked storage media. CryptoLocker then demands payment via Bitcoin or MoneyPak and installs a countdown clock on the victim’s desktop that ticks backwards from 72 hours. Victims who pay the ransom receive a key that unlocks their encrypted files; those who let the timer expire before paying risk losing access to their files forever.

Or, at least, that’s how it worked up until a few days ago, when the crooks behind this scam began easing their own rules a bit to accommodate victims who were apparently willing to pay up but simply couldn’t jump through all the hoops necessary in the time allotted.

“They realized they’ve been leaving money on the table,” Abrams said. “They decided there’s little sense in not accepting the ransom money a week later if the victim is still willing to pay to get their files back.”

Part of the problem, according to Abrams, is that few victims even know about Bitcoins or MoneyPak, let alone how to obtain or use these payment mechanisms.

“We put up survey and asked how many [victims] had paid the ransom with Bitcoins, and almost no one said they did, Abrams said. “Most paid with MoneyPak. The people who did pay with Bitcoins said they found the process for getting them was so cumbersome that it took them a week to figure it out.”

Another major stumbling block that prevents many otherwise willing victims from paying the ransom is, ironically, antivirus software that detects CryptoLocker — but only after the malware has locked the victim’s most prized files with virtually uncrackable encryption.

“Originally, when antivirus software would clean a computer, it would remove the CryptoLocker infection, which made it so the user could not pay the ransom,” Abrams said. “Newer versions change the desktop background to include a URL where the user can download the infection again and pay the ransom.”

The idea of purposefully re-infecting a machine by downloading and executing highly destructive malware may be antithetical and even heresy to some security pros. But victims who are facing the annihilation of their most precious files probably have a different view of the situation. Abrams that said his testing has shown that as long as the registry key “HKCU\Software\Cryptolocker_0388″ remains in the Windows registry, re-downloading the malware would not try to re-encrypt the already encrypted data — although it would encrypt any new files added since the initial infection.

“Some antivirus companies have been telling victims not to pay the ransom,” Abrams said. “On the one hand, I get it, because you don’t want to encourage these malware writers. But on the other hand, there are some companies that are facing going out of business if they don’t, and can’t afford to take the holier-that-thou route.”

CRYPTOLOCKER DECRYPTION SERVICE

On Friday, Nov. 1, the crooks behind this malware campaign launched a “customer service” feature that they have been promising to debut for weeks: a CryptoLocker Decryption Service. “This service allow [sic] you to purchase private key and decrypter for files encrypted by CryptoLocker,” the site reads. “Customers” of the service can search for their “order number” simply by uploading any of the encrypted files.

“They’re calling it an ‘order,’ as if victims posted an order at Amazon.com,” Abrams said.

The "Cryptolocker Decryption Service."

The “Cryptolocker Decryption Service.”

“If you already purchased private key using CryptoLocker, then you can download private key and decrypter for free,” explains the service, which is currently hosted at one of several addresses on the Tor anonymity network. The decryption service site is not reachable from the regular Internet; rather, victims must first download and install special software to access the site — yet another potential hurdle for victims to jump through.

According to Abrams, victims who are still within the initial 72-hour countdown clock can pay the ransom by coughing up two Bitcoins — or roughly $200 using a MoneyPak order. Victims who cannot pay within 72 hours can still get their files back, but for that unfortunate lot the ransom rises fivefold to 10 bitcoins — or roughly USD $2,232 at current exchange rates. And those victims will no longer have the option to pay the ransom via MoneyPak.

Abrams said the service exposes two lies that the attackers have been perpetuating about their scheme. For starters, the bad guys have tried to dissuade victims from rolling back their system clocks to buy themselves more time to get the money together and pay the ransom. According to Abrams, this actually works in many cases to delay the countdown timer. Secondly, the launch of the Cryptolocker Decryption Service belies the claim that private keys needed to unlock files encrypted by CryptoLocker are deleted forever from the attacker’s servers after 72 hours.

Continue reading →


8
Jul 13

Styx Exploit Pack: Domo Arigato, PC Roboto

Not long ago, miscreants who wanted to buy an exploit kit — automated software that helps booby-trap hacked sites to deploy malicious code  — had to be fairly well-connected, or at least have access to semi-private underground forums. These days, some exploit kit makers are brazenly advertising and offering their services out in the open, marketing their wares as browser vulnerability “stress-test platforms.”

Styx Pack victims, by browser and OS version.

Styx Pack victims, by browser and OS version.

Aptly named after the river in Greek mythology that separates mere mortals from the underworld, the Styx exploit pack is a high-end software package that is made for the underground but marketed and serviced at the public styx-crypt[dot]com. The purveyors of this malware-as-a-service also have made a 24 hour virtual help desk available to paying customers.

Styx customers might expect such niceties for the $3,000 price tag that accompanies this kit. A source with access to one Styx kit exploit panel that was apparently licensed by a team of bad guys shared a glimpse into their operations and the workings of this relatively slick crimeware offering.

The Styx panel I examined is set up for use by a dozen separate user accounts, each of which appears to be leveraging the pack to load malware components that target different moneymaking schemes. The account named “admin,” for example, is spreading an executable file that tries to install the Reveton ransomware.

Other user accounts appear to be targeting victims in specific countries. For example, the user accounts “IT” and “IT2” are pushing variants of the ZeuS banking trojan, and according to this Styx panel’s statistics page, Italy was by far the largest source of traffic to the malicious domains used by these two accounts. Additional apparently country-focused accounts included “NL,” AUSS,” and “Adultamer” (“amer” is a derisive Russian slur used to describe Americans).

ZeuS Trojan variants targeted at Italian victims were detected by fewer than 5 out 17 antivirus tools.

ZeuS Trojan variants targeted at Italian victims were detected by fewer than 5 out 17 antivirus tools.

An exploit kit — also called an “exploit pack” (Styx is marketed as “Styx Pack”) is a software toolkit that gets injected into hacked or malicious sites, allowing the attacker to foist a kitchen sink full of browser exploits on visitors. Those visiting such sites with outdated browser plugins may have malware silently installed.

Unlike other kits, Styx doesn’t give a detailed breakdown of the exploits used in the panel. Rather, the panel I looked at referred to its bundled exploits by simple two-digit numbers. This particular Styx installation used just four browser exploits, all but one of which targets recent vulnerabilities in Java. The kit referred to each exploit merely by the numbers 11, 12, 13 and 32.

According to the considerable legwork done by Kafeine, a security blogger who digs deeply into exploit kit activity, Styx Kit exploit #11 is likely to be CVE-2013-1493, a critical flaw in a Java browser plugin that Java maker Oracle fixed with an emergency patch in March 2013. Exploit 12 is almost certainly CVE-2013-2423, another critical Java bug that Oracle patched in April 2013. In an instant message chat, Kafeine says exploit #13 is probably CVE-2013-0422, a critical Java vulnerability that was patched in January 2013. The final exploit used by the kit I examined, number 32, maps to CVE-2011-3402, the same Microsoft Windows font flaw exploited by the Duqu Trojan.

The Styx stats page reports that the hacked and malicious sites used by this kit have been able to infect roughly one out of every 10 users who visited the sites. This particular Styx installation was set up on June 24, 2013, and since that time it has infected approximately 13,300 Windows PCs — all via just those  four vulnerabilities (but mostly the Java bugs).

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