Analysis by: Augusto II Remillano

 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: Dropped by other malware, Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size: 1,357,824 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 Oct 2018
Payload: Connects to URLs/IPs, Steals information

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 copies of itself into the affected system and executes them:

  • %Application Data%\{string1}{string2}\{string1}{string2}.exe
    • {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 and executes the following files:

  • %User Temp%\{random folder name}\{random filename}.bat = used to delete originally executed copy of itself. 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} = %Application Data%\{string1}{string2}\{string1}{string2}.exe

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}\
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}
Main = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Block = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Temp = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Client = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Ini = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Keys = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Install = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
LastTask = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
LastConfig = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
CrHook = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
OpHook = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Exec = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
NetCfg = "{hex value}"

Dropping Routine

This Trojan Spy drops the following files:

  • %User Temp%\{random filename}.bin
  • %User Temp%\{random filename}.bin1

(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:

  • System information
  • Keyboard logs
  • Browser cookies
  • Email credentials
  • Clipboard logs
  • Installed software
  • List of computers and devices on the network
  • IP address
  • Currently running processes
  • Installed drivers

Other Details

This Trojan Spy connects to the following website to send and receive information:

  • https://{BLOCKED}heck.com/images/{random path}.{jpeg | gif | bmp}
  • https://{BLOCKED}la.com/images/{random path}.{jpeg | gif | bmp}

It does the following:

  • Saves stolen information in a file and then uploads it
  • Monitors Internet browsing activities
  • Hooks APIs of target processes
  • Disables SPDY protocol
  • Executes the following commands:
    • cmd /C "systeminfo.exe > %User Temp%\{random filename}.bin1"
    • cmd /C "net view >> %User Temp%\{random filename}.bin1"
    • cmd /C "nslookup 127.0.0.1 >> %User Temp%\{random filename}.bin1"
    • cmd /C "tasklist.exe /SVC >> %User Temp%\{random filename}.bin1"
    • cmd /C "driverquery.exe >> %User Temp%\{random filename}.bin1"
    • cmd /C "reg.exe query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" /s >> %User Temp%\{random filename}.bin1"
    • cmd /U /C "type %User Temp%\{random filename}.bin1 > %User Temp%\{random filename}.bin & del %User Temp%\{random filename}.bin1"
    • makecab.exe /F "%User Temp%\{random filename}.bin

(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.)

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.596.08
FIRST VSAPI PATTERN DATE: 30 Oct 2018
VSAPI OPR PATTERN File: 14.597.00
VSAPI OPR PATTERN Date: 31 Oct 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} = %Application Data%\{string1}{string2}\{string1}{string2}.exe

Step 6

Search and delete this file

[ 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 folder name}\\{random filename}.bat
  • %User Temp%\\{random filename}.bin
  • %User Temp%\\{random filename}.bin1

Step 7

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