TSPY_URSNIF.YXS
TrojanSpy:Win32/Ursnif!rfn (Microsoft),
Windows
Threat Type: Spyware
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
This spyware may be downloaded by other malware/grayware from remote sites. It may be dropped by other malware.
It connects to certain websites to send and receive information. It deletes itself after execution.
TECHNICAL DETAILS
352,256 bytes
EXE
Yes
25 Oct 2015
Connects to URLs/IPs
Arrival Details
This spyware may be downloaded by the following malware/grayware from remote sites:
- http://{BLOCKED}l.by/aa.jpg
It may be dropped by the following malware:
- W2KM_DRIDEX.YXS
Installation
This spyware drops the following copies of itself into the affected system and executes them:
- %Application Data%\{8 random character folder name}\{8 random character file name}.exe
(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 injects codes into the following process(es):
- explorer.exe
- opera.exe
- chrome.exe
- iexplore.exe
- firefox.exe
Autostart Technique
This spyware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{8 random character value name} = "%Application Data%\{8 random character folder name}\{8 random character file name}.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{random GUID}
It adds the following registry entries:
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{random GUID}
Install = "{encrypted file path of the dropped copy}"
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{random GUID}
Client = "{hex value}"
Download Routine
This spyware downloads an updated copy of itself from the following website(s):
- http://{BLOCKED}.{BLOCKED}.5.24/{4 digit number}{u or c}.exe
Information Theft
This spyware gathers the following data:
- Online banking credentials
- Keystroke logs
Other Details
This spyware connects to the following website to send and receive information:
- {BLOCKED}lowdisallow.me
- {BLOCKED}isallowallow.me
- {BLOCKED}tagentdisa.me
- {BLOCKED}otjclientcli.me
- {BLOCKED}pcliallow.me
- {BLOCKED}ntaxpalagent.me
- {BLOCKED}lalaxp.mn
- {BLOCKED}lientclient.me
- {BLOCKED}liclient.me
- {BLOCKED}nothing.me
It deletes itself after execution.
NOTES:
The random variables {8 random character value name}, {8 random character folder name} and {8 random character file name} are combinations of first four characters of the file name of a .DLL file and last four characters of another .DLL file found in the Windows system folder.
It uses domain generation algorithm (DGA) for its C&C servers. Once it connects to its C&C, it downloads its configuration file which contains the target online banking sites and web inject scripts.
SOLUTION
9.800
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Remove the malware/grayware file dropped/downloaded by TSPY_URSNIF.YXS. (Note: Please skip this step if the threat(s) listed below have already been removed.)
- W2KM_DRIDEX.YXS
Step 4
Restart in Safe Mode
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {8 random character value name} = "%Application Data%\{8 random character folder name}\{8 random character file name}.exe"
- {8 random character value name} = "%Application Data%\{8 random character folder name}\{8 random character file name}.exe"
Step 6
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\AppDataLow\Software\Microsoft
- {random GUID}
- {random GUID}
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_URSNIF.YXS. 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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