TROJ_SHARIK.LS
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.
It modifies the Internet Explorer Zone Settings.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
383,488 bytes
EXE
No
05 Feb 2014
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 drops the following copies of itself into the affected system:
- %All Users Profile%\Application Data\{random folder name 1}\{random name 1}.exe
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
{KEY}\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
shell = "%All Users Profile%\Application Data\{random folder name}\{random name}.exe,explorer.exe"
{KEY}\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{random key} = "%All Users Profile%\Application Data\{random folder}\{random file name}.exe"
Web Browser Home Page and Search Page Modification
This Trojan modifies the Internet Explorer Zone Settings.
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}cconverter.biz
It drops the following file(s)/component(s):
- %All Users Profile%\Application Data\{random folder name 2}\{random name 2}.{3 random letters}
- %SystemRoot%\{random name}.{3 random letters}
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
It deletes the initially executed copy of itself
NOTES:
It connects to the following randomized domain with the ff. extensions:
- .info
- .com
- .biz
- .org
- .net
- .ru
Where {KEY} can be the ff.:
- HKEY_CURRENT_USER
- HKEY_USERS \.DEFAULT
- HKEY_USERS \{SID}
SOLUTION
9.300
10.585.80
04 Feb 2014
10.586.00
05 Feb 2014
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
Scan your computer with your Trend Micro product and note files detected as TROJ_SHARIK.LS
Step 3
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In
{KEY}\Software\Microsoft\Windows
NT\CurrentVersion\Winlogon
- shell = "%All
Users Profile%\Application Data\{random folder name}\{random
name}.exe,explorer.exe"
- shell = "%All
Users Profile%\Application Data\{random folder name}\{random
name}.exe,explorer.exe"
- In
{KEY}\Software\Microsoft\Windows\CurrentVersion\RunOnce
- {random key} =
"%All Users Profile%\Application Data\{random folder}\{random file
name}.exe"
- {random key} =
"%All Users Profile%\Application Data\{random folder}\{random file
name}.exe"
Step 4
Search and delete these files
- %All Users Profile%\Application Data\{random folder name 2}\{random name 2}.{3 random letters}
- %SystemRoot%\{random name}.{3 random letters}
Step 5
Reset Internet security settings
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_SHARIK.LS. 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.
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