This is a polymorphic stealth virus. It hooks INT 1, 3, 1Ch, 21h and writes itself to the end of COM- and EXE-files that are executed. While creating, opening and executing COM- and EXE-files it stores their names, and hits them on the files closing. On opening of infected files the virus disinfects them. On FindFirst/Next DOS calls it "decreases" the infected file length. The virus deletes CHKLIST.* files, while execution of CHKDSK utility it disables its FindFirst/Next handler, while execution of MKS anti-virus scanner is stops the infection. It disables the debugging of the virus code by hooking INT 1, 3.
On May, from 28th till 31th the virus overwrites the hard drive sectors with the strings:
DIGI POWER Then it manifests itself with the video and sound effects, and displays the message:
DIGI POWER THIS IS A NEW ... DELIVER II SÆëâlÆH (R) WRITE BY DiGiT! ... SOUTH POLAND 1995
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Virus.DOS.Deliver.Digi.3547 is a dangerous memory resident polymorphic encrypted stealth virus...