Analysis by: John Anthony Banes
ALIASES:

Trojan-Spy.Win32.Ursnif.zpc (Kaspersky); Win32/Spy.Ursnif.BW trojan (NOD32)

 THREAT SUBTYPE:

Fileless

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Trojan Spy arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It connects to certain websites to send and receive information. It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 322,560 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 12 Sep 2018
Payload: Drops files, Connects to URLs/IPs, Displays windows, Compromises system security

Arrival Details

This Trojan Spy 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 Trojan Spy drops the following files:

  • %User Temp%\{random string).err - deleted afterwards
  • %User Temp%\{random string).dll - deleted afterwards
  • %User Temp%\{random string).cmdline - deleted afterwards
  • %User Temp%\{random string).pdb - deleted afterwards
  • %User Temp%\{random string).tmp - deleted afterwards
  • %User Temp%\{random string).out - deleted afterwards
  • %User Temp%\{random string).0.cs - deleted afterwards

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

It injects codes into the following process(es):

  • explorer.exe

Autostart Technique

This Trojan Spy adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{string1}{string2} = cmd.exe /C powershell invoke-expression([System.Text.Encoding]::ASCII.GetString((get-itemproperty 'HKCU:\Software\AppDataLow\Software\Microsoft\{GUID}').{string1}{string2}))

Other System Modifications

This Trojan Spy 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}
{UID} = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
{Value Name} = "{hex value}"
where {Value Name} may be any of the following:

  • Main
  • Block
  • Temp
  • Client
  • Client32
  • Ini
  • Keys
  • Scr
  • Kill
  • LastTask
  • LastConfig
  • Exec
  • TorClient
  • TorCrc

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
EnableSPDY3_0 = "0"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
{string1}{string2} = $ylpvpgxk="kqcx";function aiyffsth{$ihruemuho=[System.Convert]::FromBase64String($args[0]);[System.Text.Encoding]::ASCII.GetString($ihruemuho);}; [byte[]]$hjbbb=@(233,43,226,0,0,0,0,0,4,0,0,0... (truncated)

Dropping Routine

This Trojan Spy drops the following files wherein it saves the information it gathers:

  • %User Temp%\{random filename}.bin
  • %User Temp%\{random filename}.bi1

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

Information Theft

This Trojan Spy gathers the following data:

  • Computer Name
  • Digital Certificates
  • Cookies
  • Keyboard Logs
  • Clipboard Logs
  • Captured Screenshot
  • Email Credentials
  • Running processes and services
  • Installed device drivers
  • Installed Programs
  • System Information (Please see notes for more details)
  • List of computer and network resources

Stolen Information

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

  • https://{BLOCKED}nqweqe.com/images/{random path}.bmp

Other Details

This Trojan Spy connects to the following URL(s) to get the affected system's IP address:

  • myip.opendns.com
  • resolver1.opendns.com

It connects to the following website to send and receive information:

  • http://{BLOCKED}lagood.fun/images/{random path}.avi

It does the following:

  • Saves stolen information in a file and then uploads it
  • Monitors Internet browsing activities
  • Hooks APIs of target process
  • Disables SPDY protocol in Mozilla Firefox
  • Executes commands to gather information:
    • systeminfo.exe
    • tasklist.exe /SVC
    • driverquery.exe
    • reg.exe query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall"
    • net view > %User Temp%\{random filename}.bi1

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

It deletes the initially executed copy of itself

NOTES:

{string1} refers to the first four letters of a .dll file in the System folder. {string2} refers to the last four letters of a .dll file in the System folder.

The file systeminfo.exe returns 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(es)
  • Network card(s)

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.500.05
FIRST VSAPI PATTERN DATE: 12 Sep 2018
VSAPI OPR PATTERN File: 14.501.00
VSAPI OPR PATTERN Date: 13 Sep 2018

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

[ Learn More ]

Step 4

Delete this registry key

[ Learn More ]

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}

Step 5

Delete this registry value

[ Learn More ]

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} = cmd.exe /C powershell invoke-expression([System.Text.Encoding]::ASCII.GetString((get-itemproperty 'HKCU:\Software\AppDataLow\Software\Microsoft\{GUID}').{string1}{string2}))
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • EnableSPDY3_0 = "0"

Step 6

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Temp%\{random string).err
  • %User Temp%\{random string).dll
  • %User Temp%\{random string).cmdline
  • %User Temp%\{random string).pdb
  • %User Temp%\{random string).tmp
  • %User Temp%\{random string).out
  • %User Temp%\{random string).0.cs
  • %User Temp%\{random filename}.bin
  • %User Temp%\{random filename}.bi1

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_URSNIF.TIBAIEB. 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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