TROJ_AGENT.BCTO
Trojan.Gen.2 (Symantec); PAK:UPX, ARC:BatToExe, PAK:[1.bat]:DebugScript (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan 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
25,600 bytes
EXE
No
20 Jun 2012
Arrival Details
This Trojan 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 Trojan creates the following folders:
- %User Temp%\1.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 Trojan deletes the following files:
- %User Temp%\1.tmp
- %System Root%\bug
- %System Root%\0.ico
- %System Root%\temp.reg
- %Temp%\scs2.tmp
- %Temp%\scs3.tmp
- %Temp%\scs4.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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
It modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop\
WindowMetrics
Shell Icon Size = "31"
(Note: The default value data of the said registry entry is 32.)
Dropping Routine
This Trojan drops the following files:
- temp.reg
- %System Root%\TMP1
- 0.ico
- %Windows%\0.ico
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.)
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
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics
- From: Shell Icon Size = "31"
To: Shell Icon Size = ""32""
- From: Shell Icon Size = "31"
Step 3
Search and delete these components
- temp.reg
- %System Root%\TMP1
- 0.ico
- %Windows%\0.ico
Step 4
Search and delete this folder
- %User Temp%\1.tmp
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT.BCTO. 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 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.
- %User Temp%\1.tmp
- %System Root%\bug
- %System Root%\0.ico
- %System Root%\temp.reg
- %Temp%\scs2.tmp
- %Temp%\scs3.tmp
- %Temp%\scs4.tmp
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