Exploit insecure malware code to retaliate against hackers: Websense

Security firms should consider exploiting coding mistakes in malware to take the security fight straight back to the hackers, a Websense security analyst has suggested in a discussion blog that outlines steps to take over the command and control (C&C) servers related to the Zeus banking Trojan.

A highly effective Trojan, Zeus was designed to steal banking and other types of personally identifiable information (PII). Despite its demonstrated efficacy, however, Websense researcher Abel Toro suggests in the blog that the Zeus code is riddled with weaknesses and that a publicly known vulnerability can be used to impersonate an infected system and upload carefully-crafted documents that to the C&C server.

The Zeus C&C servers expect stolen PII to be encrypted using the RC4 encryption technique and the server's encryption key. However, the analyst noted, RC4 is a 'symmetric cipher' so both the client Trojan and server use the same key – which means that the key must be contained somewhere within the malware itself.

Using the Volatility memory analysis tool, the RC4 key can be extracted and used to encrypt a web-shell payload that can be loaded onto the target C&C server using techniques that trick it into running the payload – which, in turn, can be exploited to gain full access to the Zeus C&C server's control panel “just as the original botnet owner would.”

“While Zeus is regarded as an 'advanced' banking Trojan it is also [subject] to bugs that may allow, in an ironic twist, an attacker with the technical skillset to take over a botnet's C&C server,” Toro says.

This approach could be used to take a more aggressive stance against malware, with suitably skilled security experts able to take on malware authors head on – for example, by proactively probing botnet attack networks or feeding their technical details to track down the suspects.

Such actions would represent an escalation of the cat-and-mouse game that currently characterises the relationship, with unknown consequences. Yet the knowledge that it can be done, the Websense blogger suggests, should at least prompt discussions about how and whether security analysts should consider a more active response to extant and new malware threats.

Hackers “are learning that it's not so easy to write secure code,” Toro says. “Most of us in the business of securing our applications and systems know that bulletproofing software is an extremely expensive and exhaustive undertaking. Malware creators who have to look to their own defences would have to slow down the production of new attacks.”

“Most attackers lack the necessary resources and community peer review to harden their malware, and that provides an opportunity for the security community to advance a conversation about what we should do about it.”

Join the CSO newsletter!

Error: Please check your email address.

Tags malware

More about Toro AustraliaWebsense

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by David Braue

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts