TSPY_URSNIF.YYSWR
TrojanSpy:Win32/Ursnif.HN (Microsoft); Win32/PSW.Papras.EH (ESET-NOD32)
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.
It deletes the initially executed copy of itself.
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 drops the following copies of itself into the affected system and executes them:
- %Application Data%\{string1}{string2}\{string1}{string2}.exe
where:
{string1} = first four letters of a dll file under %System% directory
{string2} = last four letters of a dll file under %System% directory
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops the following component file(s):
- %User Temp%\{random filename}.bin
(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.)
It drops and executes the following files:
- %User Temp%\{random folder name}\{random filename}.bat ← use to delete itself; deleted afterwards
(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.)
It creates the following folders:
- %Application Data%\{string1}{string2}
where:
{string1} = first four letters of a dll file under %System% directory
{string2} = last four letters of a dll file under %System% directory
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
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
{string1}{string2} = "%Application Data%\{string1}{string2}\{string1}{string2}.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}\
Vars
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}\
Files
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}\
Run
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}\
Config
It adds the following registry entries:
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
{Value Name} = "{hex value}"
where {Value Name} may any of the following:
- Block
- Client
- Install
- LastTask
- CrHook
- OpHook
HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
{UID} = "{hex value}"
Other Details
This spyware connects to the following possibly malicious URL:
- http://{domain}/{r/g/q}{random}.php?{random}={b64 encoded data}
where {domain} can be any of the following:- {BLOCKED}s.{BLOCKED}e.com
- {BLOCKED}owerltd.in
- {BLOCKED}man9.in
It deletes the initially executed copy of itself
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
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
Restart in Safe Mode
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
- {string1}{string2} = "%Application Data%\{string1}{string2}\{string1}{string2}.exe"
- {string1}{string2} = "%Application Data%\{string1}{string2}\{string1}{string2}.exe"
Step 5
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
- {GUID}
- {GUID}
Step 6
Search and delete this file
- %User Temp%\{random folder name}\{random filename}.bat
- %User Temp%\{random filename}.bin
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_URSNIF.YYSWR. 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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