TSPY_GOLROTED.YZAT

 Analysis by: Pearl Charlaine Espejo

 ALIASES:

TrojanSpy:MSIL/Golroted.B (Microsoft)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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 modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size:

1,051,648 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

19 Aug 2015

Payload:

Connects to URLs/IPs

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 files:

  • %Application Data%\Microsoft\Windows\isshost.exe - detected as TROJ_LOADER.NHH

(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 non-malicious files:

  • %Application Data%\pid.txt - contains the process id of the malware
  • %Application Data%\pidloc.txt - contains full name and path of malware
  • %User Temp%\holdermail.txt
  • %User Temp%\SysInfo.txt
  • %User Temp%\Login Data

(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.. %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 the following copies of itself into the affected system:

  • %Application Data%\Windows Update.exe
  • %Application Data%\Microsoft\Windows\dslsvc.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.)

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
Windows Update = "%Application Data%\WindowsUpdate.exe"

Other System Modifications

This spyware modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "1"

(Note: The default value data of the said registry entry is "2".)

Web Browser Home Page and Search Page Modification

This spyware modifies the Internet Explorer Zone Settings.

Information Theft

This spyware gathers the following data:

  • Computer name
  • Local Date and Time
  • Installed Language
  • .Net Version
  • Operating System Platform
  • Operating System Version
  • Internal IP Address
  • External Ip Address
  • Installed Antivirus
  • Installed Firewall
  • Key logs
  • Clipboard logs
  • Computer Screenshot
  • Account information from:
    • Bitcoin
    • Minecraft
    • Steam
    • RuneScape

It attempts to steal stored email credentials from the following:

  • MS Outlook
  • MS Outlook Express
  • Gmail
  • Google Talk
  • Google Picasa
  • GMail Notifier
  • Google Desktop Search Mail
  • Yahoo! Mail
  • IncrediMail
  • Mozilla Thunderbird
  • FoxMail
  • Windows Live Mail
  • MSN Messenger
  • Pidgin Messenger
  • Paltalk Messenger
  • Miranda Messenger
  • Windows Credential Manager
  • Internet Account Manager

It attempts to get stored information such as user names, passwords, and hostnames from the following browsers:

  • Internet Explorer
  • Google Chrome
  • Opera
  • Firefox
  • Apple Safari
  • Flock
  • Chrome SXS
  • CoolNovo
  • SeaMonkey
  • Comodo Dragon

Stolen Information

This spyware sends the data it gathers to the following email addresses via SMTP:

  • {BLOCKED}inky101@amakiri.eu

Other Details

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

  • http://whatismyipaddress.com/

NOTES:

This spyware may also send the data it gathers through:

  • FTP
  • WebPanel
    • http://{BLOCKED}.{BLOCKED}.212.64/WebPanel/log.php?username={username}&name={generated value}&data={stolen data}

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.864.05

FIRST VSAPI PATTERN DATE:

19 Aug 2015

VSAPI OPR PATTERN File:

11.865.00

VSAPI OPR PATTERN Date:

20 Aug 2015

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 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
    • Windows Update = "%Application Data%\WindowsUpdate.exe"

Step 5

Restore this modified 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\Explorer\Advanced
    • From: Hidden = "1"
      To: Hidden = "2"

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.
  • %Application Data%\Microsoft\Windows\isshost.exe
  • %Application Data%\pid.txt
  • %Application Data%\pidloc.txt
  • %User Temp%\holdermail.txt
  • %User Temp%\SysInfo.txt
  • %User Temp%\Login Data

Step 7

Reset Internet security settings

[ Learn More ]

Step 8

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