TSPY_GOLROTED.YZAE
TrojanSpy:MSIL/Golroted.B (Microsoft); RDN/Generic PWS.y (McAfee); Trojan.Gen.2 (Symantec); Trojan-PSW.Win32.Heye.ayv (Kaspersky); Mal/Generic-L (Sophos); Trojan horse Atros.CAGD (AVG)
Windows
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 Profile%\Application Data\mSILlzCwXB
(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.)
Other System Modifications
This spyware modifies the following file(s):
- %Application Data%\GDIPFONTCACHEV1.DAT
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It deletes the following files:
- {malware path and file name}:zone.identifier
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\RegAsm
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\RegAsm\
DEBUG
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"
(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
EventMessageFile = "%System%\ESENT.dll"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryMessageFile = "%System%\ESENT.dll"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryCount = "1"
(Note: The default value data of the said registry entry is 10.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
TypesSupported = "7"
(Note: The default value data of the said registry entry is 7.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "1"
(Note: The default value data of the said registry entry is 2.)
Dropping Routine
This spyware drops the following files:
- %User Profile%\mSILlzCwXB\8466.xml
- %User Startup%\n72t6bI.lnk
- %User Profile%\Application Data\pid.txt
- %User Profile%\Application Data\pidloc.txt
(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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
Other Details
This spyware connects to the following possibly malicious URL:
- {BLOCKED}.248.172
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
Delete this registry key
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_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process
- RegAsm
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process\RegAsm
- DEBUG
Step 3
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\Software\Microsoft\GDIPlus
- From: FontCachePath = "%Application Data%"
To: FontCachePath = ""%User Profile%\Local Settings\Application Data""
- From: FontCachePath = "%Application Data%"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: EventMessageFile = "%System%\ESENT.dll"
To: EventMessageFile = ""{random values}""
- From: EventMessageFile = "%System%\ESENT.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: CategoryMessageFile = "%System%\ESENT.dll"
To: CategoryMessageFile = ""{random values}""
- From: CategoryMessageFile = "%System%\ESENT.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: CategoryCount = "1"
To: CategoryCount = ""10""
- From: CategoryCount = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: TypesSupported = "7"
To: TypesSupported = ""7""
- From: TypesSupported = "7"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "1"
To: Hidden = ""2""
- From: Hidden = "1"
Step 4
Search and delete these components
- %User Profile%\mSILlzCwXB\8466.xml
- %User Startup%\n72t6bI.lnk
- %User Profile%\Application Data\pid.txt
- %User Profile%\Application Data\pidloc.txt
Step 5
Search and delete this folder
- %User Profile%\Application Data\mSILlzCwXB
Step 6
Scan your computer with your Trend Micro product to delete files detected as TSPY_GOLROTED.YZAE. 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 7
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.
- %Application Data%\GDIPFONTCACHEV1.DAT
Step 8
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.
- {malware path and file name}:zone.identifier
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