Posts Tagged: bleepingcomputer.com


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 →


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 →