Feeds

Zombie PC herders issue commands from Tor hideout

Bury command server deep in the onion

Boost IT visibility and business value

Security researchers have discovered a botnet that uses the Tor anonymiser network to hide its command nodes.

Owners of the compromised network of Windows PCs have placed their command-and-control server, which uses the common IRC protocol, as a hidden service inside of the Tor network. Aside from the use of Tor for extra anonymity and stealth, the zombie network is otherwise unremarkable, according to security researchers at German security firm G Data.

The botnet is capable of lending itself towards either running DDoS attacks, adware or secondary malware distribution, among other scams.

Botnet owners have moved from running a central C&C server (subject to takedown) to using a peer-to-peer architecture over recent years. P2P systems give every zombie in a botnet the ability to issue commands to other drones. However, this introduces other problems for cybercrooks because it creates a means for either rival scammers or the authorities to take over their botnet, unless a strong and difficult-to-apply authentication mechanism is built into the systems to thwart potential hijacks.

Cybercrooks have also experimented with Twitter as a control channel, but the approach has not really caught on.

Tor is generally known as a web anonymization service but the technology also creates a handy means to build an IRC server as hidden service, a potential exploited by botherders.

This novel approach brings all sorts of advantages for zombie PC herders, as G-Data explains.

 Since the server is anonymous, it cannot point towards the botnet owners' identity. Botnet control traffic is encrypted by Tor, so it can't be blocked by Intrusion Detection Systems monitors (a standard component of modern enterprise security systems). Blocking Tor traffic in general is problematic because there are legitimate uses for the technology.

In addition, Tor servers can't easily taken down. Although Tor tends to be slow and unreliable, due to in-built latency, this minor disadvantage is more than offset by the many advantages Tor offers as a venue for a botnet command server.

G-Data's analysis of what it describes as the "latest evolution in botnet C&C" can be found here. ®

Gartner critical capabilities for enterprise endpoint backup

More from The Register

next story
Microsoft: We plan to CLEAN UP this here Windows Store town
Paid-for apps that provide free downloads? Really
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
e-Borders fiasco: Brits stung for £224m after US IT giant sues UK govt
Defeat to Raytheon branded 'catastrophic result'
Hear ye, young cyber warriors of the realm: GCHQ wants you
Get involved, get a job and then never discuss work ever again
Chinese hackers spied on investigators of Flight MH370 - report
Classified data on flight's disappearance pinched
Microsoft cries UNINSTALL in the wake of Blue Screens of Death™
Cache crash causes contained choloric calamity
prev story

Whitepapers

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.
7 Elements of Radically Simple OS Migration
Avoid the typical headaches of OS migration during your next project by learning about 7 elements of radically simple OS migration.
BYOD's dark side: Data protection
An endpoint data protection solution that adds value to the user and the organization so it can protect itself from data loss as well as leverage corporate data.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?