In a statement, BitDefender says that Trojan.Spy.YEK sniffs for critical data and archives that may hold private information and sends them back to the attacker.

BitDefender Malware Researchers Doina Cosovan and Octavian Minea say that because Trojan.Spy.YEK has both spying and backdoor features, it is a serious enemy.

"A spying malware in the local network of a company means danger and unfortunately the number of such threats is constantly increasing," the researchers said.

"With an encrypted dll in its overlay, this Trojan is easily saved in windows\system32\netconf32.dll and once injected in explorer.exe nothing can stop it from connecting (whenever necessary) to a couple of meeting spots with the attacker," the researchers said.