Feeds

Zombie PC herders issue commands from Tor hideout

Bury command server deep in the onion

SANS - Survey on application security programs

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. ®

Combat fraud and increase customer satisfaction

More from The Register

next story
Parent gabfest Mumsnet hit by SSL bug: My heart bleeds, grins hacker
Natter-board tells middle-class Britain to purée its passwords
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
Obama allows NSA to exploit 0-days: report
If the spooks say they need it, they get it
Web data BLEEDOUT: Users to feel the pain as Heartbleed bug revealed
Vendors and ISPs have work to do updating firmware - if it's possible to fix this
Snowden-inspired crypto-email service Lavaboom launches
German service pays tribute to Lavabit
One year on: diplomatic fail as Chinese APT gangs get back to work
Mandiant says past 12 months shows Beijing won't call off its hackers
Call of Duty 'fragged using OpenSSL's Heartbleed exploit'
So it begins ... or maybe not, says one analyst
prev story

Whitepapers

Designing a defence for mobile apps
In this whitepaper learn the various considerations for defending mobile applications; from the mobile application architecture itself to the myriad testing technologies needed to properly assess mobile applications risk.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.