Modified by: Joachim Suico
ALIASES:

PWS:Win32/Dyzap.M (Microsoft); Infostealer.Dyranges (Norton); Trojan.Win32.Staser.aypa (Kaspersky)

 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: Dropped by other malware, Downloaded from the Internet

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 connects to certain websites to send and receive information. It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 528,896 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 11 Feb 2015
Payload: Compromises system security, 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 copies of itself into the affected system and executes them:

  • %Windows%\{random filename}.exe (for Windows XP and lower)
  • %AppDataLocal%\{random filename}.exe (for Windows Vista and higher)

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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 files:

  • %System%\config\systemprofile\Application Data\f5e83w4ef.dat (for Windows XP and lower)
  • %AppDataLocal%\f5e83w4ef.dat (Windows Vista and higher)

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\zx5fwtw4ep

It injects codes into the following process(es):

  • svchost.exe
  • explorer.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\googleupdate
ImagePath = "%Windows%\{random filename.exe}" (for Windows XP and lower)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\googleupdate
Display = "Google Update Service" (for Windows XP and lower)

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
GoogleUpdate = "%AppDataLocal%\{random filename}.exe" (for Windows Vista and higher)

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\googleupdate (for Windows XP and lower)

Information Theft

This spyware s configuration file contains the following information:

  • List of strings related to banking/bitcoin (if connections to C&C servers are successful)
  • Proxy address for Man-in-the-middle attack (if connections to C&C servers are successful)

It gathers the following data:

  • Computer Name
  • Host Name
  • Public IP Address
  • OS Version
  • User Name
  • OS platform
  • Installed programs

Other Details

This spyware connects to the following URL(s) to check for an Internet connection:

  • google.com
  • microsoft.com

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

  • http://icanhazip.com

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

  • {BLOCKED}.{BLOCKED}.50.42:443
  • {BLOCKED}.{BLOCKED}.223.61:443
  • {BLOCKED}.{BLOCKED}.0.247:4443
  • {BLOCKED}.{BLOCKED}.20.157:4443
  • {BLOCKED}.{BLOCKED}.14.145:443
  • {BLOCKED}.{BLOCKED}.123.76:443
  • {BLOCKED}.{BLOCKED}.99.67:443
  • {BLOCKED}.{BLOCKED}.69.150:443
  • {BLOCKED}.{BLOCKED}.3.4:443
  • {BLOCKED}.{BLOCKED}.19.156:443
  • {BLOCKED}.{BLOCKED}.99.70:443
  • {BLOCKED}.{BLOCKED}.74.36:4443
  • {BLOCKED}.{BLOCKED}.20.157:4443
  • {BLOCKED}.{BLOCKED}.62.169:443
  • {BLOCKED}.{BLOCKED}.89.29:443
  • {BLOCKED}.{BLOCKED}.109.60:443
  • {BLOCKED}.{BLOCKED}.132.136:443
  • {BLOCKED}.{BLOCKED}.253.52:443
  • {BLOCKED}.{BLOCKED}.190.26:443
  • {BLOCKED}.{BLOCKED}.190.178:443
  • {BLOCKED}.{BLOCKED}.190.167:443
  • {BLOCKED}.{BLOCKED}.0.247:4443
  • {BLOCKED}.{BLOCKED}.253.52:4443
  • {BLOCKED}.{BLOCKED}.213.146:443
  • {BLOCKED}.{BLOCKED}.213.146:4443
  • {BLOCKED}.{BLOCKED}.223.61:443
  • {BLOCKED}.{BLOCKED}.223.61:4443
  • {BLOCKED}.{BLOCKED}.204.113:443
  • {BLOCKED}.{BLOCKED}.197.178:443
  • {BLOCKED}.{BLOCKED}.232.226:4443
  • {BLOCKED}.{BLOCKED}.191.200:443
  • {BLOCKED}.{BLOCKED}.216.100:4443
  • {BLOCKED}.{BLOCKED}.237.139:443
  • {BLOCKED}.{BLOCKED}.189.92:443
  • {BLOCKED}.{BLOCKED}.171.213:443
  • {BLOCKED}.{BLOCKED}.40.17:443
  • {BLOCKED}.{BLOCKED}.191.217:443
  • {BLOCKED}.{BLOCKED}.191.218:443
  • {BLOCKED}.{BLOCKED}.175.236:443
  • {BLOCKED}.{BLOCKED}.139.97:443
  • {BLOCKED}.{BLOCKED}.142.226:4443
  • {BLOCKED}.{BLOCKED}.125.167:443
  • {BLOCKED}.{BLOCKED}.49.21:443
  • {BLOCKED}.{BLOCKED}.142.18:443
  • {BLOCKED}.{BLOCKED}.119.17:443
  • {BLOCKED}.{BLOCKED}.48.199:443
  • {BLOCKED}.{BLOCKED}.48.114:443
  • {BLOCKED}.{BLOCKED}.49.152:443

It does the following:

  • Monitors the following browsers: chrome.exe, firefox.exe, iexplore.exe
  • Connects to the following STUN (Session Traversal Utilities for NAT) server in order to determine the public IP address of the compromised computer: stun1.voiceeclipse.net, stun.callwithus.com, stun.sipgate.net, stun.ekiga.net, stun.ideasip.com, stun.internetcalls.com, stun.noc.ams-ix.net, stun.phonepower.com, stun.voip.aebc.com, stun.voipbuster.com, stun.voxgratia.org, stun.ipshka.com, stun.faktortel.com.au, stun.iptel.org, stun.voipstunt.com, stunserver.org, 203.183.172.196:3478, s1.taraba.net, s2.taraba.net, stun.l.google.com:19302, stun1.l.google.com:19302, stun2.l.google.com:19302, stun3.l.google.com:19302, stun4.l.google.com:19302, stun.schlund.de, stun.rixtelecom.se, stun.voiparound.com, numb.viagenie.ca, stun.stunprotocol.org, stun.2talk.co.nz
  • Receive configuration(web injects)
  • Receive New connections
  • Download Module(VNC,TV)
  • Browser Snapshot
  • Shutdown/restart system

It deletes itself after execution.

NOTES:
It can send and receive information on the following I2P network for secure connection:

  • {BLOCKED}cr5xvl5jlrhyxjktcdi2d7k5cqeulu4mdl75xxfwmhgnsq.b32.i2p:443

It sends the following GET request:

  • /1102us1/{Computer name}_{OS platform}.{variable}/{number}/{variable request type}/{BLOCKED}.{BLOCKED}.43.38/

If the hardcoded C&C is inaccessible, it may connect to the following DGA URLs to send and receive information:

  • {pseudo random alphanumeric characters}.so
  • {pseudo random alphanumeric characters}.tk
  • {pseudo random alphanumeric characters}.cn
  • {pseudo random alphanumeric characters}.hk
  • {pseudo random alphanumeric characters}.in
  • {pseudo random alphanumeric characters}.to
  • {pseudo random alphanumeric characters}.ws
  • {pseudo random alphanumeric characters}.cc

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.472.08
FIRST VSAPI PATTERN DATE: 11 Feb 2015
VSAPI OPR PATTERN File: 11.473.00
VSAPI OPR PATTERN Date: 12 Feb 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\googleupdate
    • ImagePath = %Windows%\{random filename}.exe (for Windows XP and lower)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\googleupdate
    • Display = "Google Update Service" (for Windows XP and lower)
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • GoogleUpdate = %AppDataLocal%\{random filename}.exe (for Windows Vista and higher)

Step 5

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.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\googleupdate (for Windows XP and lower)

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.
  • %System%\config\systemprofile\Application Data\f5e83w4ef.dat (for Windows XP and lower)
  • %AppDataLocal%\f5e83w4ef.dat (for Windows Vista and higher)

Step 7

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


Did this description help? Tell us how we did.