Christmas Tree EXEC
Christmas Tree EXEC was the first widely disruptive computer worm, which paralyzed several international computer networks in December 1987. The virus ran on the IBM VM/CMS operating system.
| Other names | CHRISTMA EXEC, CHRISTMAS EXEC |
|---|---|
| Original author(s) | Unknown Clausthal University of Technology student |
| Initial release | December 1987 |
| Written in | REXX |
| Platform | IBM System/370 |
| Type | Computer worm, malware, trojan horse |
Written by a student at the Clausthal University of Technology in the REXX scripting language, it drew a crude Christmas tree as text graphics, then sent itself to each entry in the target's email contacts file. In this way it spread onto the European Academic Research Network (EARN), BITNET, and IBM's worldwide VNET. On all of these systems it caused massive disruption.
The core mechanism of the ILOVEYOU worm of 2000 was essentially the same as Christmas Tree, although it ran on PCs rather than mainframes, was spread over a different network, and was scripted using VBScript rather than REXX.