PE_URSNIF.E-O

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.

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 adds the following folders:

• %Application Data%\{string 1}{string 2}

(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 drops the following copies of itself into the affected system:

• %Application Data%\{string 1}{string 2}\{string 1}{string 2}.exe
• %System%\{string 1}{string 2}.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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Its DLL component is injected to the following process(es):

• explorer.exe
• iexplore.exe
• firefox.exe
• chrome.exe

Autostart Technique

This spyware 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\spsrv
DisplayName = "Windows Protection"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\spsrv
ImagePath = "%System%\{string1}{string 2}.exe -k"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\spsrv
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\spsrv
DependOnService = "RPCSS"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\spsrv
Description = "This Windows service enables the download, installation and enforcement of digital licenses for Windows and Windows applications. If the service is disabled, the operating system and licensed applications may run in a notification mode. It is strongly recommended that you not disable the Software Protection service."

It adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{string 1}{string 2} = "%Application Data%\{string 1}{string 2}\{string 1}{string 2}.exe"

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\spsrv

File Infection

This spyware infects the following files:

• *.pdf
• *.msi
• *.doc
• *.xls
• *.ppt
• *.docx
• *.xlsx
• *.pptx

  It infects these files found in removable and network drives

  Infected files are detected as PE_URSNIF.E

Propagation

This spyware drops copies of itself in the following drives:

• removable drives
• network drives

It drops copies of itself in network drives such as the following:

• {drive letter}:\{Folder Name}.exe

It drops the following copy(ies) of itself in all removable drives:

• {drive letter}:\{Folder Name}.exe

Information Theft

This spyware gathers the following data:

• Running processes and services
• Installed device drivers
• Programs installed
• Screenshots
• System Information (Please see notes for more details)

Stolen Information

This spyware sends the gathered information via HTTP POST to the following URL:

• http://{BLOCKED}.{BLOCKED}.127.119/pki/mscorp/crl/msitwww2.crl
• http://{BLOCKED}.{BLOCKED}.127.119/pki/mscorp/crl/MSIT%20Machine%20Auth%20CA%202(1).crl

Other Details

This spyware does the following:

• It hooks the following WININET.DLL exported functions when the DLL component is loaded in IEXPLORE.EXE to monitor network traffic:
  • HttpOpenRequestA
  • HttpOpenRequestW
  • HttpSendRequestA
  • HttpSendRequestW
  • HttpQueryInfoA
  • HttpQueryInfoW
  • InternetReadFile
  • InternetReadFileExA
  • InternetReadFileExW
  • InternetQueryDataAvailable
• It hooks the following NSS3.DLL or NSPR4.DLL exported functions when the DLL component is loaded in FIREFOX.EXE to monitor network traffic:
  • PR_Read
  • PR_Write
  • PR_Close
  • PR_Poll
  • PR_Available
• It hooks unnamed functions exported by CHROME.DLL when the DLL component is loaded in CHROME.EXE to monitor network traffic.
• If CHROME.DLL is not found, it will hook the following APIs exported by KERNEL32.DLL:
  • LoadLibraryA
  • LoadLibraryW
  • LoadLibraryExA
  • LoadLibraryExW
• It will drop and execute a temporary file, %User Temp%\~{random}.tmp, which is responsible in injecting its embedded DLL component to the said processes stated above. The temporary file will terminate and delete itself, 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.)

NOTES:

where:

• {string1} = first part of the file name from any file found in %System%
• {string2} = end part of the file name from any file in %System%
(e.g. cmdlnsta.exe = cmdl32.exe + rwinsta.exe)

It issues the following commands in Command Prompt (cmd) to gather its stolen information:

• systeminfo
• tasklist /SVC (enumerate processes and services)
• driverquery (gather information on installed drivers)
• reg.exe query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" /s (gather installed programs)

Systeminfo will return the following system information:

• Host Name
• OS Name, Version, Manufacturer, Configuration and Build Type
• Registered Owner and Organization
• Product ID
• Original Install Date
• System Up Time
• System Manufacturer, Model and type
• Processor(s)
• BIOS version
• Windows and System directory
• Boot Device
• System and Input Locale
• Time Zone
• Total and Available Memory
• Virtual Memory information (Max, Available, In Use)
• Page file locations
• Domain
• Logon server
• Hotfix(s)
• Network card(s)

The information gathered will be saved to temporary file %User Temp%\~{random}.tmp, which serves as its stolen information dump/log file. After the file is sent to its C&C server, the malware will delete it.