Computer security pro Prevx claims to have discovered a new Trojan which is "guaranteed" to evade major anti-virus products to steal financial details.
Versions of Limbo 2 is apparently being sold by hackers for as much as $1300.
Prevx explains: "The strength of the Limbo 2 Trojan lies in its highly changeable shell, which hackers customise for each new customer, allowing it to stay undetected by major anti-virus companies".
"Whilst the payload and end result is the same, this pliable cloak has practically unlimited variants, allowing Limbo 2 to slip past the major AV vendors unnoticed."
"Each variant sold is built anew and has to be customised to incorporate the domain of where all the information is to be sent back to. These are then sold on to websites or botnets to infect individuals."
The Trojan is being used to steal financial information and hijack live banking sessions, "not only keylogging from information fed in by the user, but also adding spoofed information boxes asking for users to enter more information than usual".
This and other information such as password logins, credit card details, email details and any other personal information stored on the hard drive are then all filtered back to the malware owner.
Jacques Erasmus, Director of Malware Research at Prevx said, "This is one of the most dangerous Trojans out there at the moment. The strength of this piece of Malware lies in its versatility, even if it is recognised up by an anti-virus company it can be changed so as to be invisible again within hours".
"There are likely to be so many variants out there that they will never all be detected, which is a scary thought as it is designed to steal bank details."
He added: "Whoever designed this Trojan is making a lot of money, probably thousands of pounds every day".