Each of the recent DDoS attacks against U.S. financial institutions have this in common: The Izz ad-din Al qassam cyber fighters have claimed credit, and the same PHP-based toolkit, "itsoknoproblembro," has been used to launch at least some of the DDoS attacks involved.
First, the attackers must install the toolkit on targeted servers. "The malicious actors make use of Web application vulnerabilities on thousands of different Web servers in order to drop various flavors of the itsoknoproblembro PHP scripts into available directories," according to the Prolexic report. "Once the files are written to the server, attackers are able to access them to perform unauthorized system functions, check on the bot's status, or launch DDoS attacks."
DDoS attacks today focus both on infrastructure (layers 3 and 4) as well as applications (layer 7), according to Prolexic.
Unlike botnets, Prolexic said that itsoknoproblembro infections aren't managed using a command-and-control (C&C) server, in which infected endpoints retrieve commands from a botmaster. Instead, the itsoknoproblembro infections are controlled by pushing commands to them.
The versatile toolkit can be used to infect a number of different systems. "Itsoknoproblembro scripts have been discovered on servers hosting a variety of platforms, including Awstats, WordPress, Joomla, Plesk, and many others. For example, one of the more popular recent infection vectors is the exploitation of vulnerability within the Joomla Bluestork theme," according to the report.
Unfortunately for U.S. banks, or anyone else targeted via itsoknoproblembro, the vulnerabilities exploited by the toolkit remain hard to fix. "Cleanup efforts for itsoknoproblembro have been extremely difficult and taxing on security experts," according to Prolexic. "Coupled with outdated Web applications and inexperienced administrators, it will be extremely difficult to effectively remediate this infection." While further efforts are underway to find new ways to spot and block related attacks, so far there's been no quick-fix defensive measure discovered.