( CNN ) -- Software giant Microsoft is offering a $ 250,000 reward for information leading to the arrest and conviction of hackers behind a powerful computer virus that could lead to millions of PCs being hijacked . Experts say a single infected laptop could expose an entire network to the worm . Experts have so far been baffled by the true purpose of the Conficker or Downadup virus , but have described its spread as one of the most serious infections ever seen . The worm exploits a bug in Microsoft Windows to infect mainly corporate networks , then -- although it has yet to cause any harm -- it opens a link back to its point of origin , meaning it can receive further orders to wreak havoc . Microsoft has issued a patch to fix the bug , however if a single machine is infected in a large network , it will spread unchecked -- often reinfecting machines that have been disinfected . The threat from the virus prompted Microsoft in collaboration with other technology industry names to this week announce a $ 250,000 reward for information to track down those behind Conficker . `` As part of Microsoft 's ongoing security efforts , we constantly look for ways to use a diverse set of tools and develop methodologies to protect our customers , '' said George Stathakopoulos , of Microsoft 's Trustworthy Computing Group . Mikko Hypponen , chief research officer at anti-virus firm F-Secure says the true scope of the virus is not known , but in the past 24 hours his company monitored Conficker signals from two million Internet protocol addresses . `` That 's a lot , '' he told CNN . `` And one IP address here does not mean one infected computer , it means at least one infected computer . `` Many of those IP addresses are obviously company proxies or firewalls , hiding hundreds of more infections behind it . Unfortunately this also makes it impossible to estimate the total count of infected systems . `` So it 's still big . Very big . '' Microsoft has previously paid out similar rewards to informants who helped identify the creator of Sasser , another notorious worm let loose in 2004 . The perpetrator was tracked to Germany , where he was sentenced a year later .
Software giant Microsoft offers $ 250,000 bounty to catch Conficker author . Industry analysts say is one of the most serious infections they have ever seen . The worm exploits a bug in Microsoft 's ubiquitous Windows software . Virus could allow its creators to hijack entire networks .