Online poker players beware: there may be someone at your table looking at your cards, and they’re not standing behind you.

A new virus making the rounds on the Internet enables cybercriminals to take screenshots of opponents’ hands on popular poker sites such as PokerStars and Full Tilt Poker, according to ESET, a Slovakian online security company.

Potential cheaters can then attempt to join the tables where victims are playing to gain an unfair advantage.

“It’s quite a benign trick,” Urban Schrott, an IT security analyst at ESET, told SiliconRepublic.com, “but I guess that’s all that really matters in poker.”

The trojan virus, Win32/Spy.Odlanor, is installed on users’ machines after downloading poker-related programs such as player databases and calculators, ESET wrote in a blog post. The virus can also be picked up by downloading applications from sources other than the official websites of software makers.