5lo

Alias:
Strain:-
detected when:
where:
Classification:EXE-infector, resident
Length:2 kilobyte(s)

Preconditions

Operating System(s):MS-DOS
Version/Release:read-only files are not infected
Computer model(s):PC's
Caroname:5lo

Attributes

Easy identification:

Type of Infection:

The virus appends itself to the files Selfrec in memory: Int21_handler[0] == 0F9F8h (CLC; STC) Selfrec on disk: File[0Ch] == 0FFAAh

Infection Technique:
Infection Trigger:(Load || Term) && (search .\*.exe) && (pag/mod Filesize== actual Filesize)
Storage Media affected:
Interrupts hooked:21/4B 21/4C
Stealth:
Tunneling/Selfprot:
Oligo/Polymorphism:-
Encoding Method:
Damage:Transient: - Permanent: -
Damage Trigger:Transient: - Permanent: -
Particularities:The virus resides above the last MCB Infected files are datestamped to the time of infection.The DTA is restored to a bogus value on exiting from the int21routine. It is possible that another file is erronuously closedif no *.exe files are found in the current directory. There areother non-specific bugs. Not displayed text: "92.05.24.5lo.2.23" There is an int3 breakpoint in the code just before the virusrelocates itself at the resident address.
Similarities:

Agents

Countermeasures:
Standard means:

Acknowledgements

Location:Virus Test Center, University Hamburg, FRG
Classification by:Adam David, Frisk Software International
Documentation by:Adam David, Frisk Software International
Date:26.7.93
Information Source:Caroentry (autom.converter by S.Freitag)

(c) 1996 Virus-Test-Center, University of Hamburg