TROJ_INJECT.YYTS
Windows
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 deletes itself after execution.
TECHNICAL DETAILS
391,680 bytes
EXE
Yes
06 Dec 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 creates the following folders:
- %User Temp%\IejeZvujh
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MecelXoran = "regsvr32.exe %User Profile%\MecelXoran\MecelXoran.dat "
Other System Modifications
This Trojan deletes the following files:
- *5
It adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Classes\
CLSID\{117A5899-70DC-4EA0-B35F-15F35AEF383F}
HKEY_CURRENT_USER\SOFTWARE\Classes\
CLSID\{6DC27B69-71ED-4D68-A596-26246E600862}
It adds the following registry entries:
HKEY_CURRENT_USER\CLSID\{117A5899-70DC-4EA0-B35F-15F35AEF383F}
#sd = "{random values}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{6DC27B69-71ED-4D68-A596-26246E600862}
{70F02777-377A-401E-81D9-18A6337C4BAD} = "{random values}"
HKEY_CURRENT_USER\CLSID\{6DC27B69-71ED-4D68-A596-26246E600862}
{70F02777-377A-401E-81D9-18A6337C4BAD} = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
TabProcGrowth = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2500 = "3"
HKEY_CURRENT_USER\CLSID\{117A5899-70DC-4EA0-B35F-15F35AEF383F}
#cert = "{random values}"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\Safer\
CodeIdentifiers
DefaultLevel = "4"
(Note: The default value data of the said registry entry is 40000.)
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\Safer\
CodeIdentifiers
TransparentEnabled = "1"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\Safer\
CodeIdentifiers
PolicyScope = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\Safer\
CodeIdentifiers
ExecutableTypes = "WSC"
(Note: The default value data of the said registry entry is {random values}.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\IejeZvujh\MecelXoran.dat
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)
Other Details
This Trojan deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.700
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
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_CURRENT_USER\SOFTWARE\Classes\CLSID
- {117A5899-70DC-4EA0-B35F-15F35AEF383F}
- In HKEY_CURRENT_USER\SOFTWARE\Classes\CLSID
- {6DC27B69-71ED-4D68-A596-26246E600862}
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\Run
- MecelXoran = "regsvr32.exe %User Profile%\MecelXoran\MecelXoran.dat "
- In HKEY_CURRENT_USER\CLSID\{117A5899-70DC-4EA0-B35F-15F35AEF383F}
- #sd = "{random values}"
- In HKEY_CURRENT_USER\Software\Classes\CLSID\{6DC27B69-71ED-4D68-A596-26246E600862}
- {70F02777-377A-401E-81D9-18A6337C4BAD} = "{random values}"
- In HKEY_CURRENT_USER\CLSID\{6DC27B69-71ED-4D68-A596-26246E600862}
- {70F02777-377A-401E-81D9-18A6337C4BAD} = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- NoProtectedModeBanner = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- TabProcGrowth = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- 2500 = "3"
- In HKEY_CURRENT_USER\CLSID\{117A5899-70DC-4EA0-B35F-15F35AEF383F}
- #cert = "{random values}"
Step 5
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_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers
- From: DefaultLevel = "4"
To: DefaultLevel = ""40000""
- From: DefaultLevel = "4"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers
- From: TransparentEnabled = "1"
To: TransparentEnabled = ""1""
- From: TransparentEnabled = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers
- PolicyScope = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers
- From: ExecutableTypes = "WSC"
To: ExecutableTypes = ""{random values}""
- From: ExecutableTypes = "WSC"
Step 6
Search and delete this file
- %User Temp%\IejeZvujh\MecelXoran.dat
Step 7
Search and delete this folder
- %User Temp%\IejeZvujh
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_INJECT.YYTS. 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 9
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.
- *5
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