Security watchers have discovered a Trojan with built in root-kit functionality that's designed to steal the credentials of online poker players.
This isn't particularly unusual in itself, but anti-virus researchers at Finnish security firm F-Secure discovered the malware was hidden in a ostensibly legitimate package offered for download at checkraised.com, a site which provides advice and tools to online poker players.
Analysis of the Trojan revealed a sophisticated and targeted attack featuring a number of malware (executable) components that a compromised package called RBCalc.exe (AKA Rakeback calculator) deposits on vulnerable Windows PCs.
"The purpose of the dropped executables is to collect login information for various online poker websites from the user's computer and send them back to the malware author. In addition, the main malware component was protected by a rootkit driver that hid its process and launch point from registry," F-Secure's researchers note in a blog entry.
After F-Secure reported the malware to checkraised.com, the site acted promptly to sanitise the software it offered for download. Checkraised.com has established a page on its site designed to offer its take on the attack and give users instructions on how to remove the malware. Checkraised.com goes on to explain that it's been offering the RBCalc.com package for download for some months, unaware of its hostile intent. The malicious behaviour of the package escaped detection by some popular security packages, checkraised.com adds.
"In December 2005 we contracted a programmer to create a rake calculator for us. The rake calculator (known as rbcalc, rbcalc.exe) was an executable file that a player would run on his machine to calculate rake from hands he previously played (stored in hand history files or a poker tracker database)," a notice on checkraised.com explains.
"It has recently come to our attention that early versions of this program that we received contained a virus that installs itself every time the user runs rbcalc. The virus goes undetected by Norton AntiVirus and Microsoft Defender, even to this day." ®