These are very dangerous memory resident parasitic viruses. They hook INT 21h and write themselves to the beginning of .COM-files that are accessed. Depending on the system timer these viruses overwrite the files with the tests:
"Vik.480": Queen Viktoria livesalleverytime in my heart!
"Vik.550": Queen ViKtoria is dead...but I have a new LIFE&LOVE!
