Super-virus Flame raises the cyberwar stakes

Flame, a stealthy and complex cyberweapon, was found to be spying on Iran's government officials and computer systems.

NEW YORK (CNNMoney) -- The "Flame" virus, the most complex computer bug ever discovered, has been lurking for years inside Iranian government computers, spying on the country's officials.

Publicly unveiled this week, the bug is one of the most potent cyber weapons ever spotted in the wild. Security professionals say it marks a new milestone in the escalating digital espionage battle.

Flame's complexity and power "exceed[s] those of all other cyber menaces known to date," research firm Kaspersky Lab wrote in a dispatch about its investigation into Flame.

In a statement posted on its website on Monday, the Iranian National Computer Emergency Response Team (CERT) said it discovered Flame after "multiple investigations" over the past few months.

COMPUTER VIRUS

A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. However, the term "virus" is commonly used, albeit erroneously, to refer to many different types of malware programs. The original virus may modify the copies, or the copies may modify themselves, as occurs in a metamorphic virus. A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or the Internet, or by carrying it on a removable medium such as a floppy disk, CD, or USB drive. Additionally, viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer. Viruses are sometimes confused with computer worms and Trojan horses. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless until executed.