Rise of ransomware and do-it-yourself botnets

by Sharon Lobo    Sep 02, 2010

Online FraudIn its August 2010 Threat Landscape report, Fortinet showed ransomware variant TotalSecurity with its biggest comeback since March. Ransomware is malware that locks out applications and data from a user’s PC and then demands ransom for restored access, and TotalSecurity loader (W32/FakeAlert.LU) was the no. 1 malware detected this month by Fortinet’s FortiGuard Labs.

“One indicator we observed this month was that the Ransomware application had gone server-side polymorphic, which means that the loader will connect to a single server and request a single file, but the code changes on an hourly basis in order to avoid detection,” said Derek Manky, project manager, cyber security and threat research, Fortinet. “This is a technique typically seen with botnets, such as Waledac, and has been picked up by the developers of TotalSecurity. This is another example of how relying purely on antivirus is not a silver-bullet approach to protecting systems from infection.”

“Do-It-Yourself” Botnet Kits
In addition to ransomware, another highly detected infection this month is Zeus/ZBot, a do-it-yourself botnet kit that provides a malware creator all of the tools required to build and administer a botnet. The Zeus tools are primarily designed for stealing banking information, but they can easily be used for other types of data or identity theft. This month, ZBot variants were noted to target U.S. military personnel. A control panelapplication is used to maintain/update the botnet, and to retrieve/organize recovered information. A configurable builder tool allows the author to create the executables that will be used to infect victim’s computers.

“We continue to monitor for in-the-wild Zeus/ZBot attacks, and due to the kit’s prevalence we continuously release antivirus detection for these when they occur,” Manky said. “Generic detection is also available to try to stay ahead of future variants, while FortiGuard web filtering will also help guard against malicious controller domains.”

One other notable attack this month is the recent Windows Help Center vulnerability, which was propelled to the front position in our top 10 attack list. The attack (CVE-2010-1885) experienced an exceptionally large spike in activity earlier in the month. Exploitation of this attack can be rather potent since the vulnerability is not Web browser-specific.