BKDR_ZEGOST.SM45
Win32/Farfli.CJT trojan(NOD32); VirTool:Win32/CeeInject.TD!bit(MICROSOFT)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Backdoor 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
Arrival Details
This Backdoor 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 Backdoor drops the following copies of itself into the affected system:
- %Program Files%\java.exe
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following processes:
- %system%\cmd.exe /c del {malware path and file name}.exe.exe.exe nul
- %Program Files%\java.exe
- %System%\svchost.exe -k WerSvcGroup
- %System%\sc.exe start w32time task_started
- %Program Files%\java.exe Win7
- %System%\WerFault.exe -u -p 1784 -s 268
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It creates the following folders:
- %All Users Profile%\Microsoft\Windows\WER\ReportQueue\AppCrash_java.exe_{random characters}
(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )
Autostart Technique
This Backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Java(TM) Platform Sa 8.02
DisplayName = "Oracle Corporation"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Java(TM) Platform Sa 8.02
ImagePath = "%Program Files%\java.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Java(TM) Platform Sa 8.02
Start = "SERVICE_AUTO_START"
It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Java(TM) Platform Sa 8.02
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Java(TM) Platform Sa 8.02\MarkTime
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Java(TM) Platform Sa 8.02\Description
Other System Modifications
This Backdoor modifies the following file(s):
- %System%\LogFiles\Scm\{random characters}
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Java(TM) Platform Sa 8.02
MarkTime = "{date of execution}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Java(TM) Platform Sa 8.02
Description = "Java(TM) Platform SE 8 Oracle Corporation"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W32Time
Type = "16"
(Note: The default value data of the said registry entry is 20.)
Dropping Routine
This Backdoor drops the following files:
- %System%\LogFiles\Scm\{random characters}
- %Windows%\Temp\WER{random characters}.tmp.WERInternalMetadata.xml
- %Windows%\Temp\WER{random characters}.tmp.hdmp
- %Windows%\Temp\WER{random characters}.tmp.appcompat.txt
- %All Users Profile%\Microsoft\Windows\WER\ReportQueue\AppCrash_java.exe_{random characters}e\WER{random characters}.tmp.appcompat.txt
- %Windows%\Temp\WER{random characters}.tmp
- %Windows%\Temp\WER{random characters}.tmp
- %Windows%\Temp\WER{random characters}.tmp
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )
Other Details
This Backdoor connects to the following possibly malicious URL:
- http://cndns.{BLOCKED}s.org
It deletes itself after execution.
SOLUTION
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Identify and terminate files detected as BKDR_ZEGOST.SM45
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
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\SYSTEM\CurrentControlSet\Services
- Java(TM) Platform Sa 8.02
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Java(TM) Platform Sa 8.02
- MarkTime
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Java(TM) Platform Sa 8.02
- Description
Step 5
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_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Java(TM) Platform Sa 8.02
- MarkTime = "{date of execution}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Java(TM) Platform Sa 8.02
- Description = "Java(TM) Platform SE 8 Oracle Corporation"
Step 6
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\SYSTEM\CurrentControlSet\services\W32Time
- From: Type = "16"
To: Type = ""20""
- From: Type = "16"
Step 7
Search and delete these components
- %System%\LogFiles\Scm\{random characters}
- %Windows%\Temp\WER{random characters}.tmp.WERInternalMetadata.xml
- %Windows%\Temp\WER{random characters}.tmp.hdmp
- %Windows%\Temp\WER{random characters}.tmp.mdmp
- %Windows%\Temp\WER{random characters}.tmp.appcompat.txt
- %All Users Profile%\Microsoft\Windows\WER\ReportQueue\AppCrash_java.exe_{random characters}\WER{random characters}.tmp.appcompat.txt
- %Windows%\Temp\WER{random characters}.tmp
- %Windows%\Temp\WER{random characters}.tmp
- %Windows%\Temp\WER{random characters}.tmp
- %Windows%\Temp\WER{random characters}.tmp
Step 8
Search and delete this folder
- %All Users Profile%\Microsoft\Windows\WER\ReportQueue\AppCrash_java.exe_WER{random characters}
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ZEGOST.SM45. 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 10
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.
- %System%\LogFiles\Scm\0d9b5d92-3a22-486d-a887-3aa21597cf27
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