TSPY_ZBOT.YUYEN
PWS:Win32/Zbot (Microsoft); Trojan.Gen.2 (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse SHeur4.BWMB (AVG)
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: Spyware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
This ZeuS variant uses random headers and changes its file extension, making it difficult to detect.
To get a one-glance comprehensive view of the behavior of this Spyware, refer to the Threat Diagram shown below.
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.
It deletes itself after execution.
TECHNICAL DETAILS
310,784 bytes
EXE
Yes
06 Jun 2014
Drops files
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\Ciusmie
(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.)
Autostart Technique
This spyware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Ilehuruhyqa = "%User Profile%\Ciusmie\ogxym.exe "
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Ilehuruhyqa = "%User Profile%\Ciusmie\ogxym.exe "
Other System Modifications
This spyware adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Chcvifhsno
HKEY_CURRENT_USER\SOFTWARE\Chcvifhsno
HKEY_CURRENT_USER\SOFTWARE\AVygrA
HKEY_LOCAL_MACHINE\SOFTWARE\AVygrA
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Chcvifhsno
License = "1bc"
HKEY_CURRENT_USER\Software\Chcvifhsno
License = "1bc"
HKEY_CURRENT_USER\Software\AVygrA
dynamicdata = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\AVygrA
dynamicdata = "{random values}"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Session Manager\SubSystems
Windows = "{random characters}"
(Note: The default value data of the said registry entry is {random values}.)
Dropping Routine
This spyware drops the following files:
- %User Profile%\Ciusmie\ogxym.exe
- %Windows%\Tasks\Security Center Update - 404626534.job
- %System%\cyneohow.exe
(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.. %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other Details
This spyware connects to the following possibly malicious URL:
- http://{BLOCKED}uck.su
- http://{BLOCKED}uck.su/b/letr/19149A6E80C97DCCB2CFD3CD
- {BLOCKED}.79.185
It deletes itself after execution.
SOLUTION
9.700
10.842.02
05 Jun 2014
10.849.00
09 Jun 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
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_LOCAL_MACHINE\SOFTWARE
- Chcvifhsno
- In HKEY_CURRENT_USER\SOFTWARE
- Chcvifhsno
- In HKEY_CURRENT_USER\SOFTWARE
- AVygrA
- In HKEY_LOCAL_MACHINE\SOFTWARE
- AVygrA
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Ilehuruhyqa = "%User Profile%\Ciusmie\ogxym.exe "
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Ilehuruhyqa = "%User Profile%\Ciusmie\ogxym.exe "
- In HKEY_LOCAL_MACHINE\SOFTWARE\Chcvifhsno
- License = "1bc"
- In HKEY_CURRENT_USER\Software\Chcvifhsno
- License = "1bc"
- In HKEY_CURRENT_USER\Software\AVygrA
- dynamicdata = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\AVygrA
- dynamicdata = "{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\SYSTEM\ControlSet001\Control\Session Manager\SubSystems
- From: Windows = "{random characters}"
To: Windows = ""{random values}""
- From: Windows = "{random characters}"
Step 6
Search and delete these components
- %User Profile%\Ciusmie\ogxym.exe
- %Windows%\Tasks\Security Center Update - 404626534.job
- %System%\cyneohow.exe
Step 7
Search and delete this folder
- %User Profile%\Application Data\Ciusmie
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YUYEN. 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.
Did this description help? Tell us how we did.