Feeds

Bank Trojan crooks trouser £800k from 30,000 Brits

How the crims outran anti-virus sniffer dogs

The essential guide to IT transformation

Analysis Trustwave SpiderLabs has revealed how criminals stole more than £800,000 (€1m) from UK bank accounts using the Zeus Windows PC malware.

The scam - which ran from June to November last year - targeted customers of six banks in Britain. It began with a flurry of emails that tricked marks into clicking on a link to a fake Facebook login page on the crooks' servers.

The bogus website then offered to install a Flash plugin upgrade that contained a bot, a piece of software that allows a hacker to control a compromised machine. Even if a victim refused to take the update, the page used the Blackhole kit to detect the computer's security vulnerabilities and exploit them to install the electronic nasty if possible.

Once in place, the bot hides itself from view and downloads the Zeus Trojan to silently install. This piece of malware then interferes with the victims' online banking transactions to quietly redirect money to "mule" accounts.

Users within the UK were specifically targeted using geo-fencing techniques that identified their location based on their internet connection. Machines in South America white listed to protect them from infection as were test machines and affiliates in the criminals' network.

Ziv Mador, director of security research at Trustwave SpiderLabs, explained that the crooks behind the assault had used the same server in Moldova associated with a previous Zeus-powered scam, which was detected in August 2010. This operational security mistake allowed his analysts to obtain access to logs and other information that allowed them to profile the attack.

Trustwave found that the money thieves managed to infect approximately 30,000 PCs, the majority of which are in the UK. The malware used more advanced cloaking techniques than the previous assault so that it could communicate with command-and-control servers while remaining undetected. In addition, the 2011 attack was on a greater scale than its 2010 predecessor and involved several affiliates, each launching bots of their own.

Detection rates of the Trojan by anti-virus software throughout the run of the attack was low and consistently under 20 per cent, according to Mador. The crooks tweaked the malware delivered via the attack every couple of days in order to outpace detection.

The brains behind the fraud

"The unique thing about this attack was the algorithm to mask transactions," Modor told El Reg regarding the way in which the thieves siphoned cash from victims' accounts. "The cybergang maintained a database of money mules and they wouldn't use a money mule again, at least until a transaction had cleared. There was a lot of automation."

The 2011 attack was carried out using the Smoke Loader tool, which centrally manages the network of compromised computers, as well as the Blackhole exploit kit; the 2010 attack relied on the less sophisticated Elixir toolkit. Each kit tries to automatically install a payload of malicious software when a victim visits a booby-trapped website by exploiting security holes in web browsers, Java runtimes, Flash players and other software.

Trustwave SpiderLabs handed its research to UK police last year. It published a series of articles into the technical details of the attack after getting the go ahead from cops, who were satisfied that disclosing this information would not compromise their investigation.

It is unclear whether any arrests have been made over this particular scam, which is all too commonplace.

The blog posts by Trustwave SpiderLabs on Zeus can be found here: part 1, part 2, part 3, part 4 and part 5.

Each is full of technical descriptions and code analysis for those that way inclined.

Meanwhile, Microsoft has named two alleged ringleaders in a banking scam that relied on the Zeus Trojan: Ukranian nationals Yevhen Kulibaba and Yuriy Konovalenko, who are serving time in UK prisons following convictions last year and now face possible US extradition proceedings.

McAfee has also published details of a £60m attempt to target the bank accounts of the well-heeled. Operation High Roller used SpyEye and Zeus, man-in-the-browser techniques and automation comparable to the Zeus caper chronicled by Trustwave SpiderLabs, but was arguably even more sophisticated. ®

Next gen security for virtualised datacentres

More from The Register

next story
e-Borders fiasco: Brits stung for £224m after US IT giant sues UK govt
Defeat to Raytheon branded 'catastrophic result'
Germany 'accidentally' snooped on John Kerry and Hillary Clinton
Dragnet surveillance picks up EVERYTHING, USA, m'kay?
Snowden on NSA's MonsterMind TERROR: It may trigger cyberwar
Plus: Syria's internet going down? That was a US cock-up
Who needs hackers? 'Password1' opens a third of all biz doors
GPU-powered pen test yields more bad news about defences and passwords
Think crypto hides you from spooks on Facebook? THINK AGAIN
Traffic fingerprints reveal all, say boffins
Rupert Murdoch says Google is worse than the NSA
Mr Burns vs. The Chocolate Factory, round three!
Microsoft cries UNINSTALL in the wake of Blue Screens of Death™
Cache crash causes contained choloric calamity
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.