Pierluigi Paganini June 30, 2013

A new variant of Zeus trojan is offered for sale in the underground. It is a Self-propagating version that exploits Facebook, the RDP and the email.

The criminal history taught us that after the diffusion of source code of malicious agent such as the popular Zeus it is possible to assist to a real explosion of cyber crimes correlated. The release on the underground market gives the possibilities to various criminal gangs to produce their customization of the virus arranging services for its sale or renting through the various Malware-as-a-Service we analyzed in the previous posts.

Cybercrime ecosystem has always benefited for the diffusion of source code of principal malware, it fuel the creation of new variants more or less sophisticated, in the specific case of Zeus Trojan the  security community detected versions able to exploit social networks or that used P2P protocol for botnet arrangement.

It’s very common to assist to the explosion in the diffusion of malware exploitation kits just few weeks after the release of source code of a malicious code. The security expert Dancho Danchev in a recent post highlighted the capability of cyber criminals coders to implement sophisticated antivirus evading techniques:

“With more high profile malware source code leaks continuing to take place, more cybercrime-friendly coders now have access to sophisticated antivirus detection bypassing techniques. Access to these techniques will definitely spark the introduction of “new” features within the coders’ own set of underground market releases in an attempt to catch up with the market leading competition.”

Danchev and his staff began monitoring an advertisement offering access to self-propagating ZeuS based source code during the last weeks.

The offer is a good starting point for a series of reflections:

Is malicious software customization a profitable business opportunity for criminal group?

The public disclosure of source code for a malicious agent does really advantage low skilled professional in the coding of their customized malware versions?

Is the underground ecosystem still dominated by vendors ‘pushing’ their product/service strategies to fuel and meet the criminal demand for these kinds of assets?

Returning to the specific case of Self-propagating ZeuS based source code/binaries the price for the source code is comprised between $160-$180 meanwhile the cost for compiled binaries is between $80-$100. The accepted payment methods are PayPal and Bitcoin.

The advertisement represents a classic example for monetization of commoditized underground market goods, such as malware source code.

The Zeus variant exploits various channels for its diffusion such as the social network Facebook, the RDP (Remote Desktop Protocol) and the email.

A close look at malware offer reveals that the variant is a modified version of a private bot that was never released in the wild. The control infrastructure includes IRC/HTTP mode and it is ongoing the development for the support of P2P protocol.

The Zeus variant also includes a feature to prevent the analysis activities of security researchers.

Danchev highlighted that the success of a proposal in the underground economy depends on the capability of the seller to give proof of the efficiency of its product and useful information for its evaluation.

Despite market capabilities of the authors and its reputation the final judgment is provided by the performance of the malware, the proposal of efficient exploitation kits and platforms gives to any cyber criminals any necessary instrument for its fraudulent activities and the public disclosure of source code are dangerous events that could fuel criminal offer growth.

Pierluigi Paganini

(Security Affairs – Zeus, Cybercrime)