PE_DZAN.A
Virus:Win32/Dzan.A (Microsoft); W32/Dzan.a (McAfee); W32.Dizan (Symantec); Virus.Win32.Dzan.a (Kaspersky); Virus.Win32.Dzan.a (v) (Sunbelt); MemScan:Trojan.Agent.ABU (FSecure)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: File infector
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
543,232 bytes
EXE
No
25 Sep 2012
Arrival Details
This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This file infector drops the following copies of itself into the affected system:
- %User Temp%\~nsu.tmp\Au_.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It creates the following folders:
- %User Temp%\~nsu.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
Other System Modifications
This file infector deletes the following files:
- %User Temp%\nsm1.tmp
- %User Temp%\~nsu.tmp\Au_.exe
- %User Temp%\~nsu.tmp\Bu_.exe
- %User Temp%\~nsu.tmp\Cu_.exe
- %User Temp%\~nsu.tmp\Du_.exe
- %User Temp%\~nsu.tmp\Eu_.exe
- %User Temp%\~nsu.tmp\Fu_.exe
- %User Temp%\~nsu.tmp\Gu_.exe
- %User Temp%\~nsu.tmp\Hu_.exe
- %User Temp%\~nsu.tmp\Iu_.exe
- %User Temp%\~nsu.tmp\Ju_.exe
- %User Temp%\~nsu.tmp\Ku_.exe
- %User Temp%\~nsu.tmp\Lu_.exe
- %User Temp%\~nsu.tmp\Mu_.exe
- %User Temp%\~nsu.tmp\Nu_.exe
- %User Temp%\~nsu.tmp\Ou_.exe
- %User Temp%\~nsu.tmp\Pu_.exe
- %User Temp%\~nsu.tmp\Qu_.exe
- %User Temp%\~nsu.tmp\Ru_.exe
- %User Temp%\~nsu.tmp\Su_.exe
- %User Temp%\~nsu.tmp\Tu_.exe
- %User Temp%\~nsu.tmp\Uu_.exe
- %User Temp%\~nsu.tmp\Vu_.exe
- %User Temp%\~nsu.tmp\Wu_.exe
- %User Temp%\~nsu.tmp\Xu_.exe
- %User Temp%\~nsu.tmp\Yu_.exe
- %User Temp%\~nsu.tmp\Zu_.exe
- %User Temp%\nso3.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
Dropping Routine
This file infector drops the following files:
- %User Temp%\nsm2.tmp
- %User Temp%\nse4.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
This report is generated via an automated analysis system.
SOLUTION
9.200
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Search and delete these components
- %User Temp%\nsm2.tmp
- %User Temp%\nse4.tmp
Step 3
Search and delete this folder
- %User Temp%\~nsu.tmp
Step 4
Scan your computer with your Trend Micro product to clean files detected as PE_DZAN.A. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 5
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\nsm1.tmp
- %User Temp%\~nsu.tmp\Au_.exe
- %User Temp%\~nsu.tmp\Bu_.exe
- %User Temp%\~nsu.tmp\Cu_.exe
- %User Temp%\~nsu.tmp\Du_.exe
- %User Temp%\~nsu.tmp\Eu_.exe
- %User Temp%\~nsu.tmp\Fu_.exe
- %User Temp%\~nsu.tmp\Gu_.exe
- %User Temp%\~nsu.tmp\Hu_.exe
- %User Temp%\~nsu.tmp\Iu_.exe
- %User Temp%\~nsu.tmp\Ju_.exe
- %User Temp%\~nsu.tmp\Ku_.exe
- %User Temp%\~nsu.tmp\Lu_.exe
- %User Temp%\~nsu.tmp\Mu_.exe
- %User Temp%\~nsu.tmp\Nu_.exe
- %User Temp%\~nsu.tmp\Ou_.exe
- %User Temp%\~nsu.tmp\Pu_.exe
- %User Temp%\~nsu.tmp\Qu_.exe
- %User Temp%\~nsu.tmp\Ru_.exe
- %User Temp%\~nsu.tmp\Su_.exe
- %User Temp%\~nsu.tmp\Tu_.exe
- %User Temp%\~nsu.tmp\Uu_.exe
- %User Temp%\~nsu.tmp\Vu_.exe
- %User Temp%\~nsu.tmp\Wu_.exe
- %User Temp%\~nsu.tmp\Xu_.exe
- %User Temp%\~nsu.tmp\Yu_.exe
- %User Temp%\~nsu.tmp\Zu_.exe
- %User Temp%\nso3.tmp
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