Hackers are using a malicious spyware that sneaks a look at the virtual poker hand of a player on popular poker sites.
They are then signing into games that the player is playing and betting against that player to increase the stakes and steal all their money.
The online scam was first spotted by experts at Eset a security firm based in San Diego and it affects people that have accounts on Full Tilt Poker and PokerStars.
The spyware is named Win32/Spy.Odlanor.
Like other Trojans on computers, the spyware is able to unwittingly install if the user downloads software or an app that is infected online.
The spyware then is able to create screenshots of the window the window of the player targeted on either Full Tilt or PokerStars, if the victim is operating one of them.
These screenshots then get sent to the remote computer of the attacker. The screenshots reveal not only the hands of the infected player but their player ID.
Both of the poker sites that have been targeted let players search for others through using this ID thus making it easy for the hacker to connect to the tables the victim is playing at.
In particular, the spyware masquerades as an installer for various different programs like mTorrent or Daemon Tools, said Eset.
In other cases, security researchers found this spyware had been loaded onto the system of the victim through programs related to poker such as Poker Calculator Pro, Tournament Shark, Poker Office and more.
Eset added that it is not sure whether this perpetrator then plays the game manually or in an automated way.
As of September 16, hundreds of users were infected with the spyware, announced Eset.
The earliest spyware, of which there have been several versions, was found in March of 2015.