The jdbgmgr.exe virus hoax involved an e-mail spam in 2002 that advised computer users to delete a file named jdbgmgr.exe because it was a computer virus. jdbgmgr.exe, which had a little teddy bear-like icon (The Microsoft Bear), was actually a valid Microsoft Windows file, the Debugger Registrar for Java (also known as Java DebugManager, hence jdbgmgr).
Featuring so odd an icon among normally dull system icons had an unexpected counterpoint: an email hoax warning users that this is a virus that somehow came into your computer and should be deleted. This hoax has taken many forms and is always very popular among non-expert users that find this icon suspicious.
The email has taken many forms, including saying its purpose was to warn Hotmail users of a virus spreading via MSN Messenger, or even to alert about a possible virus in the orkut web community. All say that it was not detected by McAfee or Norton AntiVirus, which is obviously true.
This email in fact could be considered some kind of virus as it has the normal life cycle of a computer virus: It comes through user mailboxes, harms the system (by deleting a file), after which the message is forwarded to multiple recipients to reinfect them. Most important, all these commands are executed by the user, making it a fail-proof virus (c.f. honor system virus).
Bruce Schneier (born January 15, 1963, pronounced "shn-EYE-er") is an American cryptographer, computer security specialist, and writer. He is the author of several books on computer security and cryptography, and is the founder and chief technology officer of BT Counterpane, formerly Counterpane Internet Security, Inc.