TSPY_COSSTA.DJ
Backdoor:Win32/Tartober.A (Microsoft); Downloader.a!cw3 (McAfee); Downloader (Symantec); Trojan.Win32.Cossta.tri (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Trojan horse Generic29.AHKP (AVG)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Spyware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This spyware 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
Arrival Details
This spyware 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 spyware creates the following folders:
- %User Temp%\~hf~
(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 spyware modifies the following file(s):
- %User Profile%\Application Data\Microsoft
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It deletes the following files:
- %Temporary Internet Files%\Content.IE5\ZSGKJKO6\study[1].htm
(Note: %Temporary Internet Files% is the Temporary Internet Files folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temporary Internet Files on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Microsoft\Windows\Temporary Internet Files on Windows Vista and 7.)
Dropping Routine
This spyware drops the following files:
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\DSS
- %User Profile%\DSS\S-1-5-21-1645522239-1292428093-682003330-1003
- d2a1
- d2a1.tmp
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
This report is generated via an automated analysis system.
SOLUTION
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 Profile%\Microsoft\Crypto
- %User Profile%\Crypto\DSS
- %User Profile%\DSS\S-1-5-21-1645522239-1292428093-682003330-1003
- d2a1
- d2a1.tmp
Step 3
Search and delete this folder
- %User Temp%\~hf~
Step 4
Scan your computer with your Trend Micro product to delete files detected as TSPY_COSSTA.DJ. 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 deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %User Profile%\Application Data\Microsoft
Step 6
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.
- %Temporary Internet Files%\Content.IE5\ZSGKJKO6\study[1].htm
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