A computer virus that may leave Microsoft Windows users vulnerable to digital hijacking is spreading through companies in the U.S., Europe and Asia, already infecting close to 9 million machines, according to a private online security firm.

Fortunately, however, it may be a dud.

Though computer bugs have become a common affliction, Finland-based F-Secure says a virus it has been tracking for the past several weeks has surged more rapidly through corporate networks than anything they’ve seen in years.

But the virus doesn’t appear to be working as its designers intended. F-Secure’s chief security adviser, Patrik Runald, said the virus’s coding suggests a type of bug that alerts computer users to bogus infections on their machines and offers to help by selling them antivirus software.

Instead, the virus is simply spreading to little effect, though it may still pose a threat to infected computers.