Posts Tagged: Iserdo


15
Jul 15

The Darkode Cybercrime Forum, Up Close

By now, many of you loyal KrebsOnSecurity readers have seen stories in the mainstream press about the coordinated global law enforcement takedown of Darkode[dot]me, an English-language cybercrime forum that served as a breeding ground for botnets, malware and just about every other form of virtual badness. This post is an attempt to distill several years’ worth of lurking on this forum into a narrative that hopefully sheds light on the individuals apprehended in this sting and the cybercrime forum scene in general.

To tell this tale completely would take a book the size of The Bible, but it’s useful to note that the history of Darkode — formerly darkode[dot]com — traces several distinct epochs that somewhat neatly track the rise and fall of the forum’s various leaders. What follows is a brief series of dossiers on those leaders, as well as a look at who these people are in real life.

ISERDO

Darkode began almost eight years ago as a pet project of Matjaz Skorjanc, a now-36-year-old Slovenian hacker best known under the hacker alisas “Iserdo.” Skorjanc was one of several individuals named in the complaints published today by the U.S. Justice Department.

Butterfly Bot customers wonder why Iserdo isn't responding to support requests. He was arrested hours before.

Butterfly Bot customers wonder why Iserdo isn’t responding to support requests. He was arrested hours before.

Iserdo was best known as the author of the ButterFly Bot, a plug-and-play malware strain that allowed even the most novice of would-be cybercriminals to set up a global cybercrime operation capable of harvesting data from thousands of infected PCs, and using the enslaved systems for crippling attacks on Web sites. Iserdo was arrested by Slovenian authorities in 2010. According to investigators, his ButterFly Bot kit sold for prices ranging from $500 to $2,000.

In May 2010, I wrote a story titled Accused Mariposa Botnet Operators Sought Jobs at Spanish Security Firm, which detailed how several of Skorjanc’s alleged associates actually applied for jobs at Panda Security, an antivirus and security firm based in Spain. At the time, Skorjanc and his buddies were already under the watchful eye of the Spanish police.

MAFI

Following Iserdo’s arrest, control of the forum fell to a hacker known variously as “Mafi,” “Crim” and “Synthet!c,” who according to the U.S. Justice Department is a 27-year-old Swedish man named Johan Anders Gudmunds. Mafi is accused of serving as the administrator of Darkode, and creating and selling malware that allowed hackers to build botnets. The Justice Department also alleges that Gudmunds operated his own botnet, “which at times consisted of more than 50,000 computers, and used his botnet to steal data from the users of those computers on approximately 200,000,000 occasions.”

Mafi was best known for creating the Crimepack exploit kit, a prepackaged bundle of commercial crimeware that attackers can use to booby-trap hacked Web sites with malicious software. Mafi’s stewardship over the forum coincided with the admittance of several high-profile Russian cybercriminals, including “Paunch,” an individual arrested in Russia in 2013 for selling a competing and far more popular exploit kit called Blackhole.

Paunch worked with another Darkode member named “J.P. Morgan,” who at one point maintained an $800,000 budget for buying so-called “zero-day vulnerabilities,” critical flaws in widely-used commercial software like Flash and Java that could be used to deploy malicious software.

Darkode admin "Mafi" explains his watermarking system.

Darkode admin “Mafi” explains his watermarking system.

Perhaps unsurprisingly, Mafi’s reign as administrator of Darkode coincided with the massive infiltration of the forum by a number of undercover law enforcement investigators, as well as several freelance security researchers (including this author).

As a result, Mafi spent much of his time devising new ways to discover which user accounts on Darkode were those used by informants, feds and researchers, and which were “legitimate” cybercriminals looking to ply their wares.

For example, in mid-2013 Mafi and his associates cooked up a scheme to create a fake sales thread for a zero-day vulnerability — all in a bid to uncover which forum participants were researchers or feds who might be lurking on the forum.

That plan, which relied on a clever watermarking scheme designed to “out” any forum members who posted screen shots of the forum online, worked well but also gave investigators key clues about the forum’s hierarchy and reporting structure.

logsruhroh

Mafi worked closely with another prominent Darkode member nicknamed “Fubar,” and together the two of them advertised sales of a botnet crimeware package called Ngrbot (according to Mafi’s private messages on the forum, this was short for “Niggerbot.” The password databases from several of Mafi’s accounts on hacked cybercrime forums included variations on the word “nigger” in some form). Mafi also advertised the sale of botnets based on “Grum” a spam botnet whose source code was leaked in 2013. Continue reading →


2
Apr 13

Fool Me Once…

When you’re lurking in the computer crime underground, it pays to watch your back and to keep your BS meter set to  ‘maximum.’ But when you’ve gained access to an elite black market section of a closely guarded crime forum to which very few have access, it’s easy to let your guard down. That’s what I did earlier this year, and it caused me to chase a false story. This blog post aims to set the record straight on that front, and to offer a cautionary (and possibly entertaining) tale to other would-be cybersleuths.

baitOn Jan. 16, 2013, I published a post titled, “New Java Exploit Fetches $5,000 Per Buyer.” The details in that story came from a sales thread posted to an exclusive subforum of Darkode.com, a secretive underground community that has long served as a bazaar for all manner of cybercriminal wares, including exploit kitsspam services, ransomware programs, and stealthy botnets. I’ve maintained a presence on this forum off and on (mostly on) for the past three years, in large part because Darkode has been a reliable place to find information about zero-days, or highly valuable threats that exploit previously unknown vulnerabilities in software — threats that are shared or used by attackers before the developer of the target software knows about the vulnerability.

I had previously broken several other stories about zero-day exploits for sale on Darkode that later showed up “in-the-wild” and confirmed by the affected vendors, and this sales thread was posted by one of the forum’s most trusted members. The sales thread also was created during a time in which Java’s maker Oracle Corp. was struggling with multiple zero-days in Java.

What I didn’t know at the time was that this particular sales thread was little more than a carefully laid trap by the Darkode administrators to discover which accounts I was using to lurk on their forum. Ironically, I recently learned of this snare after white/grey hat hackers compromised virtually all of the administrator accounts and private messages on Darkode.

“Looks like Krebs swallowed the bait, and i got an idea how to catch him now for the next thread,” wrote Darkode administrator “Mafi” in a Jan. 16 private message to a co-admin who uses the nickname “sp3cial1st”.

Following this post, the administrators compared notes as to which users had viewed the fake Java zero-day sales thread during the brief, two-day period it was live on a restricted portion of Darkode. “I have taken a careful examination of the logs related to the java 0day thread,” sp3cial1st wrote to a Darkode administrator who used the nick “187”.

Continue reading →


29
Nov 11

Attempted Malvertising on KrebsOnSecurity.com

Members of an exclusive underground hacker forum recently sought to plant malware on KrebsOnSecurity.com, by paying to run tainted advertisements through the site’s advertising network — Federated Media. The attack was unsuccessful thanks to a variety of safeguards, but it highlights the challenges that many organizations face in combating the growing scourge of “malvertising.”

Last week, I listed the various ways this blog and its author has been “honored” over the past few years by the cybercrime community, but I neglected to mention one recent incident: On May 27, 2011, several hackers who belong to a closely guarded English-language criminal forum called Darkode.com sought to fraudulently place a rogue ad on KrebsOnSecurity.com. The ad was made to appear as though it was advertising BitDefender antivirus software. Instead, it was designed to load a malicious domain: sophakevans. co. cc, a site that has been associated with pushing fake antivirus or “scareware.”

The miscreants agreed to pay at least $272 for up to 10,000 impressions of the ad to be run on my site. Fortunately, I have the opportunity to review ads that come through Federated’s system. What’s more, Federated blocked the ad before it was even tagged for approval.

Darkode members plot to purchase a rogue ad on KrebsOnSecurity.com. They failed.

I learned about this little stunt roughly at the same time it was being planned; Much to the constant annoyance of the site administrators, I secretly had gained access to Darkode and was able to take this screen shot of the discussion. The incident came just a few weeks after I Tweeted evidence of my presence on Darkode by posting screenshots of the forum. The main administrator of Darkode, a hacker who uses the nickname “Mafi,” didn’t appreciate that, and promised he and his friends had something fun planned for me. I guess this was it. Interestingly, Mafi also is admin at malwareview.com and is the developer of the Crimepack exploit kit.

Continue reading →


28
Jul 10

Alleged Mariposa Botnet Author Nabbed

Police in Slovenia have arrested a 23-year-old man in Maribor believed to be responsible for creating the Mariposa botnet, a collection of hacked PCs that spanned an estimated 12 million computers across the globe, according to reports.

The Associated Press cites FBI officials in Washington, D.C. stating that authorities had arrested “Iserdo,” the nickname used by the hacker alleged to have created Mariposa, a botnet that first surfaced in December 2008 and grew to infect more than half of the Fortune 1,000 companies, as well as at least 40 major banks.

Earlier this year, police in Spain arrested three of Iserdo’s associates, who allegedly used the Mariposa botnet to steal credit card accounts and online banking credentials.

The AP story doesn’t identify Iserdo, saying officials declined to release his name and the exact charges filed against him, but says that the arrest took place about 10 days ago, and that the man has been released on bond.

According to information obtained by KrebsOnSecurity.com, Iserdo’s real name is Dejan Janžekovic. Local Slovenian press reports at the time of his arrest said Iserdo was a former student at the Maribor Faculty of Computer and Information Science, but that information could not be independently confirmed.

Individuals close to the case say Janžekovic charged a few hundred dollars for each copy of the bot kit, and that sales frequently were handled by a former classmate who accepted Western Union transfers on his behalf. According to two sources, one of those who helped with the transactions was a 24-year-old woman named Nuša Čoh, pictured here in her high school photo.

Neither Janžekovic nor Čoh could be immediately reached for comment.

Update, July 29, 4:45 p.m: Janzekovic appears only to have been a person of interest in this investigation, according to a law enforcement official I spoke with today. Also, I heard back from Janzekovic himself, who acknowledged having been investigated by the FBI and Slovenian police in connection with Mariposa, and taken in to the police station for questioning. But he said he is not Iserdo, and that the authorities somehow had him mixed up with someone else. From his e-mail to me:

“I am 23 years old (the picture you found is very outdated). I am single, I work as a senior systems administrator for a telco in Slovenia. Fact is that I love technology, I love life (even though the past two weeks it was hell on earth for me), but most of all – I am innocent. Yes, you read right, innocent. I am smarter than this and such things do interest me only from the technological point, as in how to protect against them.

Oh, not to forget, my net nick was and will never be Iserdo.

It is true, that I had the FBI and Slovenian police investigating me but it is also true, that I had nothing to hide. During the investigation I was very cooperative with authorities – I even gave them password for my encrypted partitions. What was the lead to me? It had to be some kind of mix-up and/or identity theft – the only person known to me in this whole story is the girl who I went to school with (as you have already found out).

Neither of authorities did explain to me how they came to conclusion that I was iserdo. I strongly believe the case was identity theft (obviously someone who knew enough about me, to know that I would easily fit in the case) and/or connection through Nusa. And believe me, it was also to my great surprise, when they woke me up at 6 a.m. to search my home on basis of me selling some ‘nasty code’.

But know this – I do not know any technical details about the botnet, program or anything about the criminal backgrounds as I have never seen it or worked with it.”

Continue reading →