Mystery hacker hijacks Dridex Trojan botnet... to serve antivirus installer

Ah, great. Ave AV


Part of the distribution channel of the Dridex banking Trojan botnet may have been hacked, with malicious links replaced by installers for Avira Antivirus.

Avira reckons the pwnage is down to the work of an unknown white hat hacker.

The Dridex botnet has remains a menace even after a high profile takedown operation in late 2015. Malicious code used to seed Dridex typically comes in the form of spam messages with malicious attachments, often a Word document embedded with malicious macros.

Once the file has been opened, the macros download the payload from a hijacked server, and the computer is infected. Dridex creates a key-logger on infected computers as well as using transparent redirects and webinjects to manipulate banking websites.

But the recent hack means part of the botnet has been requisitioned to quite different ends. “The content behind the malware download URL has been replaced, it’s now providing an original, up-to-date Avira web installer instead of the usual Dridex loader,” explained Moritz Kroll, a malware expert at Avira.

The end result is that instead of the Dridex malware that they would have received, victims get a valid, signed copy of Avira instead.

“We still don't know exactly who is doing this with our installer and why – but we have some theories,” said Kroll. “This is certainly not something we are doing ourselves.”

One possible, though unlikely, explanation is that cybercrooks are distributing anti-malware software, essentially to mess with the head of security firms and perhaps throw them off their game. A more likely scenario is that a white hat hacker has taken over botnet control systems and is in the process of trolling VXers.

“A whitehat may have hacked into infected web servers using the same vulnerabilities the malware authors used in the first place and has replaced the bad stuff with the Avira installer,” explained Kroll, adding that (whatever their motivations) these types of actions would be illegal in many countries.

The whole curious incident is not without its precedents. The Avira installer has been added to CryptoLocker and Tesla ransomware in the past. “With CryptoLocker, the malware was in many, but not all cases, expecting CnC communication, so the executable would not be accepted and Avira could not be executed. And at that time, we saw that many of the changes were at one specific provider,” said Kroll.

With Tesla, the motive behind including the Avira installer is still unclear. ®

Similar topics

Broader topics


Other stories you might like

  • DuckDuckGo tries to explain why its browsers won't block some Microsoft web trackers
    Meanwhile, Tails 5.0 users told to stop what they're doing over Firefox flaw

    DuckDuckGo promises privacy to users of its Android, iOS browsers, and macOS browsers – yet it allows certain data to flow from third-party websites to Microsoft-owned services.

    Security researcher Zach Edwards recently conducted an audit of DuckDuckGo's mobile browsers and found that, contrary to expectations, they do not block Meta's Workplace domain, for example, from sending information to Microsoft's Bing and LinkedIn domains.

    Specifically, DuckDuckGo's software didn't stop Microsoft's trackers on the Workplace page from blabbing information about the user to Bing and LinkedIn for tailored advertising purposes. Other trackers, such as Google's, are blocked.

    Continue reading
  • Despite 'key' partnership with AWS, Meta taps up Microsoft Azure for AI work
    Someone got Zuck'd

    Meta’s AI business unit set up shop in Microsoft Azure this week and announced a strategic partnership it says will advance PyTorch development on the public cloud.

    The deal [PDF] will see Mark Zuckerberg’s umbrella company deploy machine-learning workloads on thousands of Nvidia GPUs running in Azure. While a win for Microsoft, the partnership calls in to question just how strong Meta’s commitment to Amazon Web Services (AWS) really is.

    Back in those long-gone days of December, Meta named AWS as its “key long-term strategic cloud provider." As part of that, Meta promised that if it bought any companies that used AWS, it would continue to support their use of Amazon's cloud, rather than force them off into its own private datacenters. The pact also included a vow to expand Meta’s consumption of Amazon’s cloud-based compute, storage, database, and security services.

    Continue reading
  • Atos pushes out HPC cloud services based on Nimbix tech
    Moore's Law got you down? Throw everything at the problem! Quantum, AI, cloud...

    IT services biz Atos has introduced a suite of cloud-based high-performance computing (HPC) services, based around technology gained from its purchase of cloud provider Nimbix last year.

    The Nimbix Supercomputing Suite is described by Atos as a set of flexible and secure HPC solutions available as a service. It includes access to HPC, AI, and quantum computing resources, according to the services company.

    In addition to the existing Nimbix HPC products, the updated portfolio includes a new federated supercomputing-as-a-service platform and a dedicated bare-metal service based on Atos BullSequana supercomputer hardware.

    Continue reading

Biting the hand that feeds IT © 1998–2022