The Game over ZeuS Trojan virus was reportedly brought under control almost a week ago - until it made its return this week.

The Trojan malware has hijacked almost a million computers worldwide, using those computers to spread spam mails and continue spreading the virus through cyber attacks. The malware was also used in coordination to steal bank credentials.

This particular Trojan, the Game over ZeuS Trojan virus is named after the binary that was used to create it, the GameOver ZeuS binary.

"Researchers at Malcovery Security say that they have intercepted a new version of the banking Trojan horse that has been distributed via malicious spam campaigns, disguised as messages from the NatWest Bank, the Essentra packing company, and M&T Bank," said Graham Clulely, a security blogger.

"Time will tell if new versions of the malware will be as successful as those that have gone before it - we can only hope that users are getting smarter about keeping their computers properly protected," Clulely adds.

Previous strains of cyber-viruses have been hunted down by security agencies around the world, including the FBI and the National Crime Agency. Several strains of computer viruses have already been brought under control, but with the revival of the Game Over ZeuS Trojan, it's clear that online criminals are looking to use the virus to steal bank credentials.

This means that hackers using the binary to tweak the viruses to create a slightly different strain can avoid detection from authorities.

"This discovery indicates that the criminals responsible for GameOver's distribution do not intend to give up on this botnet even after suffering one of the most expansive botnet takeovers/takedowns in history," security analysts Brendan Griffin and Gary Warner say in a blog post.