Gotcha (Legalize)

Alias:
Strain:-
detected when:
where:
Classification:COM and EXE infector, resident
Length:81 paragraph(s)

Preconditions

Operating System(s):MS-DOS
Version/Release:DOS >= 3.10
Computer model(s):PC's
Caroname:Gotcha

Attributes

Easy identification:

Type of Infection:

The virus appends itself to the files Selfrec in memory: INT_21;AX=DADA -> AH=A5 (AL=15 in this version) Selfrec on disk: File[12h] == 4021h

Infection Technique:
Infection Trigger:(Loadexec || Close) && (Ext in {"EXE","COM"}) &&(300h < COM_size%64k < 0F000h)
Storage Media affected:
Interrupts hooked:21/4B00, 21/3E, 21/DADA, 24
Stealth:
Tunneling/Selfprot:
Oligo/Polymorphism:-
Encoding Method:
Damage:Transient: replaces the current program with another program which iscontained within the virus. The new program self-unpacks, displaysa "LEGALIZE CAnnAbIS" poster if the video mode is suitable (modes2, 3 or 7, otherwise just writes the text "Legalize Cannabis"), andasks for a keypress before continuing. Then the user is presented witha simple quiz about whether Cannabis should be legalised. It acceptsy/n/Y/N answers and responds according to the answers given.(question 1)Do you think Cannabis should be legalized? (Y/N)(answer yes)I'm glad you agree with me!(answer no, so ask question 2)And what about Alcohol, should that be illegal too? (Y/N)(answer yes)Hmm, I don't agree with you but I respect your opinion.(answer no)You are a HYPOCRITE!!! Permanent: -
Damage Trigger:Transient: Install_Succeeded && Day_of_Week == Friday Permanent: -
Particularities:The virus resides above the last MCB The virus disables the keyboard. Displayed text: (see TRANSIENT_DAMAGE: above); Encrypted Not displayed text: " LEGALIZE " The payload program is 1138 bytes and uncompresses itself to 4186bytes when run. It is a later version of the payload carried by theGIRAFE virus, but the compression method seems to be less effective.The actual virus code is on the whole pretty well-written.
Similarities:GIRAFE

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:20.6.93
Information Source:Caroentry (autom.converter by S.Freitag)

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