The paper, by Igor Muttik, a senior architect at McAfee's Avert Labs, says the in-game economies of virtual worlds are being hijacked by criminals.
In the "Securing Virtual Worlds Against Real Attacks - The Challenges of Online Game Development" paper, Muttik says criminals are attempting to hide their profits through the exchange of virtual currencies.
"Typically, when a gaming account is compromised, attackers will convert the objects they steal into virtual currency, and then convert the virtual currency into real money," says Muttik.
The paper also says scammers are increasingly using virtual worlds to steal private data for fraud.
Poor scripting in some online games allows some viruses to auto-execute and propagate.
There are also phishing attempts and spam messages luring members to malicious sites for "free" games.