Cybercrooks are running a wide-ranging password-guessing attack against some of the most widely used blogging and content management systems on the net.
The so-called Fort Disco cracking campaign began in late May this year and is still ongoing, DDoS mitigation firm Arbor Networks warns. Arbor has identified six command-and-control (C&C) systems associated with Fort Disco that collectively control a botnet of over 25,000 infected Windows servers. More than 6,000 Joomla, WordPress, and Datalife Engine installations have been the victims of password guessing.
Four strains of Windows malware are associated with the campaign, each of which caused infected machines to phone home to a hard-coded command and control domain.
"It’s unclear exactly how the malware gets installed," said Matthew Bing, a security researcher at Arbor Networks in a blog post on the attack. "We were able to find reference to the malware’s original filename (maykl_lyuis_bolshaya_igra_na_ponizhenie.exe) that referred to Michael Lewis’ book The Big Short: Inside The Doomsday Machine in Russian with an executable attachment."
"Another filename, proxycap_crack.exe, refers to a crack for the ProxyCap program. It’s unclear if victims were enticed to run these files, and if so, if that is the only means of infection. The C&C sites did not offer additional clues as to the infection mechanism," he added.
The top three countries with infections are the Philippines, Peru, and Mexico. curiously, it seems the US and Western Europe are underrepresented in the attack, which appears to be using zombie PCs in Latin America and the Philippines to target blogs and content management systems with the “weakest of the weak” passwords, predominantly in Russia and the Ukraine.
Only three types of platforms are under attack: Joomla (/administrator/index.php), WordPress (/wp-login.php), and Datalife Engine (/admin.php). Attackers are using compromised credentials to install a variant of the “FilesMan” PHP backdoor. This password-protected backdoor allows the attacker to browse the filesystem, upload or download files, and execute commands. Arbor has found more than 700 blogs and content management systems compromised in this way.
The ultimate aim of the attack remains, for now at least, unclear, but may involve an attempt to serve exploit kits from compromised sites. This is a continuation of a recent trend of targeting blogs and content management systems to create a powerful platform for cyberattacks, as Arbor notes.
"Beginning with the Brobot attacks in early 2013, we’ve seen attackers focusing on targeting blogs and content management systems," Arbor's Bing concludes. "This marks a tactical change in exploiting weak passwords and out-of-date software on popular platforms. By uploading a PHP shell to compromised sites, an attacker can easily issue commands to thousands of compromised sites in seconds."
"Blogs and CMSs tend to be hosted in data centres with immense network bandwidth. Compromising multiple sites gives the attacker access to their combined bandwidth, much more powerful than a similarly sized botnet of home computers with limited network access by comparison. While we have no evidence the Fort Disco campaign is related to Brobot or denial-of-service activity, we’ve experienced the threat that a large blog botnet can deliver." ®
Fort Disco is named after one of the strings found in the executable metadata field, which inadvertently left publicly accessible log files that paint a complete picture of the campaign.