Feeds

Botnet buries commands in image files

Stego backdoor hub

Internet Security Threat Report 2014

Security researchers have identified a botnet that borrows an idea from steganography by burying commands in jpg images.

The DlKhora botnet, which is primarily geared towards downloading other strains of malware, encodes instructions so that the command and control server appears to be serving up image files, SecureWorks reports.

The server sets the HTTP Content-Type header to “image/jpeg” and prefaces the bot commands with a fake 32-byte JPEG header. The bot checks if the header matches and decodes the rest of the response to retrieve its commands. The commands are encoded using a single byte XOR with 0×4.

The botnet makes no attempt to pad files such that they resemble genuine image files, a factor that marks the servers used by DlKhora out for detection. Malware installed by the botnet agent, as identified by SecureWorks to date, largely consists of ad hijacking nuisances.

Hackers need a method for passing instructions to the Trojan of compromised machines that form part of zombie (botnet) networks. IRC channels used to be the preferred venue for command and control channel but recently this has changed with miscreants experimented with different control channels such as Google Groups, Twitter and now "image" servers. ®

Top 5 reasons to deploy VMware with Tegile

More from The Register

next story
'Regin': The 'New Stuxnet' spook-grade SOFTWARE WEAPON described
'A degree of technical competence rarely seen'
You really need to do some tech support for Aunty Agnes
Free anti-virus software, expires, stops updating and p0wns the world
You stupid BRICK! PCs running Avast AV can't handle Windows fixes
Fix issued, fingers pointed, forums in flames
Regin: The super-spyware the security industry has been silent about
NSA fingered as likely source of complex malware family
Privacy bods offer GOV SPY VICTIMS a FREE SPYWARE SNIFFER
Looks for gov malware that evades most antivirus
Patch NOW! Microsoft slings emergency bug fix at Windows admins
Vulnerability promotes lusers to domain overlords ... oops
HACKERS can DELETE SURVEILLANCE DVRS remotely – report
Hikvision devices wide open to hacking, claim securobods
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
5 critical considerations for enterprise cloud backup
Key considerations when evaluating cloud backup solutions to ensure adequate protection security and availability of enterprise data.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Choosing a cloud hosting partner with confidence
Download Choosing a Cloud Hosting Provider with Confidence to learn more about cloud computing - the new opportunities and new security challenges.