TROJ_INJECT.US
W32/Kryptik.ALRY!tr (Fortinet)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
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
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.
It may be downloaded from the following remote sites:
- http://{BLOCKED}.{BLOCKED}.255.89/world/mypic.dll
Installation
This Trojan drops the following files:
- %ProgramData%\{reversed malware filename}js (Windows Vista and higher versions)
- %ProgramData%\{reversed malware filename}.pad (Windows Vista and higher versions)
- %All Users Profile%\{reversed malware filename}.js (Windows Vista and higher versions)
- %All Users Profile%\{reversed malware filename}.pad (Windows Vista and higher versions)
- %All Users Profile%\Application Data\{reversed malware filename}.js (Versions lower than Windows Vista)
- %All Users Profile%\Application Data\{reversed malware filename}.pad (Versions lower than Windows Vista)
(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %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 drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %User Startup%\runctf.lnk
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
2500 = "3"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
2500 = "3"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
2500 = "3"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2500 = "3"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
2500 = "3"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = "1"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1609 = "0"
(Note: The default value data of the said registry entry is "1".)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1609 = "0"
(Note: The default value data of the said registry entry is "1".)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1609 = "0"
(Note: The default value data of the said registry entry is "1".)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1609 = "0"
(Note: The default value data of the said registry entry is "1".)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1609 = "0"
(Note: The default value data of the said registry entry is "1".)
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
Restart in Safe Mode
Step 3
Search and delete this file
- %ProgramData%\{reversed malware filename}js (Windows Vista and higher versions)
- %ProgramData%\{reversed malware filename}.pad (Windows Vista and higher versions)
- %All Users Profile%\{reversed malware filename}.js (Windows Vista and higher versions)
- %All Users Profile%\{reversed malware filename}.pad (Windows Vista and higher versions)
- %All Users Profile%\Application Data\{reversed malware filename}.js (Versions lower than Windows Vista)
- %All Users Profile%\Application Data\{reversed malware filename}.pad (Versions lower than Windows Vista)
- %User Startup%\runctf.lnk
Step 4
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 HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
- 2500 = "3"
- 2500 = "3"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
- 2500 = "3"
- 2500 = "3"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
- 2500 = "3"
- 2500 = "3"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- 2500 = "3"
- 2500 = "3"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
- 2500 = "3"
- 2500 = "3"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- NoProtectedModeBanner = "1"
- NoProtectedModeBanner = "1"
Step 5
Restore this modified 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 HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0
- From: 1609 = "0"
To: 1609 = "1"
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
- From: 1609 = "0"
To: 1609 = "1"
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
- From: 1609 = "0"
To: 1609 = "1"
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- From: 1609 = "0"
To: 1609 = "1"
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
- From: 1609 = "0"
To: 1609 = "1"
- From: 1609 = "0"
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_INJECT.US. 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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