Purdue University College of Liberal Arts

Information Technology

About Virus Hoaxes

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Is it a real virus? Before warning others, check here first

False warnings, especially when spread by well-meaning individuals, can cause significant panic and damage.Before passing along a warning, check to see if it's a known hoax:

If the warning you received is a known hoax, simply delete the message.

If, after searching the on-line hoax database, you believe the warning is legitimate, please do not send the warning to others. Instead, contact your department's computing support staff.

Over the last several years, many people with good intentions have been sending messages alerting friends and colleagues about purported computer viruses that aren't real.

Some messages warn that merely opening e-mail messages which have specific subject lines will cause viral mayhem on your computer. Other messages try to convince you that the presence of certain files (such as jdbgmgr.exe) on your computer indicate you have a virus -- files which are, in fact, legitimate parts of the operating system.

In almost every case, such virus "warnings" are hoaxes.

Here's what to do. You should ignore these false warnings, and you should not forward the warning message to others. When in doubt, always check with your department's, school's, or employer's computing support staff (or another authoritative source) before taking any action. False warnings cause unnecessary worry and confusion.

If you received the false warning from a friend or colleague, feel free to mention this web page (www.cla.purdue.edu/it/docs/virus/hoaxes) to him or her.

"Don't open that message or a virus will erase your hard drive!!" Hoaxes like these are typically described using some combination of the following (or similar) phrases:
  • "If you get an e-mail that says 'You've won a trip!' or 'Holiday in California!' [or any of dozens of different subject lines] then DO NOT OPEN IT! It will erase your hard drive!"
  • IBM, AOL, Microsoft, and/or the FCC is said to have made the announcement.
  • The virus might be said to be "much worse than 'Melissa.'"
  • "Forward this warning to everyone in your address book!"

It is highly unlikely that a virus can be constructed to behave in the manner ascribed in such warnings. Generally, merely opening an e-mail message can not cause a virus to activate.

Of course, it's possible to activate a virus by opening a file that is attached to an e-mail message, which is why we advise that you use your e-mail program's attachment features with determined caution. See the QuickTip titled "Viruses and E-Mail Attachments" for details.

"There's a virus called 'jdbgmgr.exe' but McAfee and Norton don't detect it!" Occasionally, people pass along a message which reads something like this:

> > > A colleague's Address Book has been infected by a virus and it was
> > > passed on to my computer. My Address Book, in turn, has also been
> > > infected.
> > >
> > THE VIRUS IS CALLED jdbgmgr.exe AND IS NOT DETECTED
> > BY NORTON OR McAFEE ANTI-VIRUS SYSTEMS.

In fact, this is not a virus. The file "jdbgmgr.exe" is a legitimate part of the Windows operating system. Although it is possible for this file to be infected by another virus, the e-mail message provides details of a hoax, and it is not based on actual events. If you receive a message with this warning, you should not follow the included instructions -- you should not delete the file. The file is not necessary to run Windows, but there are circumstances in which you might need it to be there.

Given that it references a file that is legitimately on your computer, this particular warning sounds even more real. Be assured that it is a hoax.

Authoritative information about this hoax is available from anti-virus software vendors. McAfee's related information is here:



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