This virus was first found in Iceland in June '89. It only infects files with names ending in .EXE. When an infected program is run, it will hide in memory by directly manipulating the Memory Control Blocks. Programs that watch out for any program "going TSR" will therefore not be able to catch it.
This virus will mark one cluster on the hard disk as bad, every time it infects a file, but it only infects one out of every 10 files executed.
Disinfection & Removal
A minor variant of this virus was later found in Saratoga. It was 642 bytes long, and had a 50% chance of infecting programs as they were executed.
This modified version appeared in Iceland in July '89. It does not use INT 21 calls like the original, but instead makes direct JMPs into the operating systems. This means that many protection programs will be unable to catch it. This variant has no effects other than replicating.
This virus was discovered in Iceland on Dec. 24th 1989. Several computers refused to run any programs at all on that date, but simply displayed the message "GleÅ’ileg j¢l" ("Merry Christmas" in Icelandic) instead. The virus is a variant of the Icelandic-2 virus, but with several minor corrections and modifications.