Malicious Trojan programmes were the first, second and third most prevalant threats facing internet users during the month of April, in a list compiled by anti-virus software supplier BitDefender.
The Conficker worm took fourth place, but Trojans occupied seven of the top ten positions in the month’s listing, with only a couple of worms, exploits and viruses breaking up the ‘Trojan parade,’ the company said.
Trojans are malicious programmes that are disguised as something innocuous or desirable, which users may be tempted to install without knowing what the software actually does.
Bitdefender said they rely solely on tricking users to spread the e-threat, and stand as the most common way that spyware is distributed.
Some notable Trojan attacks include that of Monster Worldwide Inc’s job search service, where a malware programme seemingly stole more than 1.6 million records belonging to several hundred thousand people. Another, the so-called Torpig Trojan, stole login credentials from approximately 250,000 online bank accounts
Bitdefender noted one newcomer for April in the form of a Trojan known as KillAV.PT.
The threat is described as a ‘utility’ malware, which kills any anti-virus or security process it can find from a long list on the target machine, preventing them from running.
The threat then decrypts and executes a downloader, which in turn downloads and installs a game password stealer.
Trojan.AutorunINF.Gen occupied first place in Bitdefender’s listing. It is not a single e-threat, but rather a generic name for Trojans which use the Autorun.INF spreading mechanism, but for which a specific signature has not been added.
Two rather old adware Trojans known as Wimad and Clicker sat in the third and second spots.