Paydirt: Vulnerabilities found to foil popular DDoS toolkit

A vulnerability in the command and control (C&C) structure of the infamous Dirt Jumper distributed denial of service (DDoS) toolkits has been detailed which can be used to foil attacks.

The toolkits were based on RussKill and had rapidly become some of the most popular DDoS in the underground market, overtaking dominant rivals like Black Energy.

Thanks to a string of simple coding vulnerabilities, it was possible to access the C&C database and server-side configuration files with open source pen testing tools, anti-DDoS vendor Prolexic said.

“With this information, it is possible to access the C&C server and stop the attack,” chief executive Scott Hammack said. “It is our duty to share this vulnerability with the security community at large.”

The company also detailed information on the Pandora DDoS toolkit, used to attack the blog of Brian Krebs last week. The toolkit used HTTP Min, HTTP Download, HTTP Combo, Socket Connect and Max Flood attacks, the latter of which was used to take down Krebs’ site.

“The HTTP Combo offers a one-two punch that targets the application and infrastructure layer simultaneously, while the Max Flood attack initiates a flood that contains a 1-million-byte payload within the POST request,” Prolexic said.

The toolkit was advertised as have having slowed the Yandex search engine – the most popular in Russia and fifth in the world – to a crawl, and could take out a typical website with 10 infected bots

The toolkit’s code was “messy” however and contained typographical errors.

Prolexic said: “Infected bots beacon to the user’s C&C panel with broken GET requests that identify the availability of the bots. In addition, a GET request in the Socket Connect attack is sent as an ‘ET’ request, which is invalid HTTP request. Some web servers such as Apache, however, will interpret the ET request as a GET request and will respond with a valid OK response. Other web servers, such as nginx, will return a Bad Request error message.