Feeds

Zombie PC herders issue commands from Tor hideout

Bury command server deep in the onion

The essential guide to IT transformation

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. ®

5 things you didn’t know about cloud backup

More from The Register

next story
Goog says patch⁵⁰ your Chrome
64-bit browser loads cat vids FIFTEEN PERCENT faster!
Chinese hackers spied on investigators of Flight MH370 - report
Classified data on flight's disappearance pinched
KER-CHING! CryptoWall ransomware scam rakes in $1 MEEELLION
Anatomy of the net's most destructive ransomware threat
NIST to sysadmins: clean up your SSH mess
Too many keys, too badly managed
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
Researchers camouflage haxxor traps with fake application traffic
Honeypots sweetened to resemble actual workloads, complete with 'secure' logins
prev story

Whitepapers

Gartner critical capabilities for enterprise endpoint backup
Learn why inSync received the highest overall rating from Druva and is the top choice for the mobile workforce.
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.
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.
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.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.