Analysis by: Johnlery Triunfante
ALIASES:

HEUR:Trojan.Java.Agent.gen (KASPERSKY); Java.Trojan.GenericGB.2659 (BITDEFENDER); Java/Adwind-AGI (SOPHOS_LITE)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

  TECHNICAL DETAILS

File Size: 687,930 bytes
File Type: JAR
Memory Resident: Yes
Initial Samples Received Date: 02 May 2017

Arrival Details

This Trojan 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 adds the following folders:

  • %Application Data%\Oracle
  • %User Profile%\iFThgqgAkys - Hidden attribute
  • %User Profile%\iFThgqgAkys\OeQJyiAmqKJ
  • %User Profile%\fUTkALeaTxM
  • %User Profile%\fUTkALeaTxM\DdWDtpinxpf

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

It drops the following files:

  • %Application Data%\Oracle\{Java Installation Files}
  • %User Profile%\iFThgqgAkys\ID.txt - contains UUID, hidden attribute
  • %User Profile%\fUTkALeaTxM\ID.txt - contains UUID
  • %User Temp%\{random string}.reg
  • %User Temp%\_0.{random number 1}.class
  • %User Temp%\_0.{random number 2}.class
  • %System%\test.txt

(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 Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Autostart Technique

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

HKCU\Software\Microsoft\
Windows\CurrentVersion\Run
fkLupiVNDXZ = "%Application Data%\Oracle\bin\javaw.exe" -jar "%User Profile% \iFThgqgAkys\LUOXZqBYDCz.JcfDag"

Other System Modifications

This Trojan adds the following registry entries:

HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
ConsentPromptBehaviorAdmin = 0

HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
ConsentPromptBehaviorUser = 0

HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = 0

HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
PromptOnSecureDesktop = 0

HKLM\SOFTWARE\Policies\
Microsoft\Windows NT\SystemRestore
DisableConfig = 1

HKLM\SOFTWARE\Policies\
Microsoft\Windows NT\SystemRestore
DisableSR = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = ".avi;.bat;.com;.cmd;.exe;.htm;.html;.lnk;.mpg;.mpeg;.mov;.mp3;.msi;.m3u;.rar;.reg;.txt;.vbs;.wav;.zip;.jar;"

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.408.05
FIRST VSAPI PATTERN DATE: 02 May 2017
VSAPI OPR PATTERN File: 13.409.00
VSAPI OPR PATTERN Date: 03 May 2017

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

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
    • fkLupiVNDXZ = "%Application Data%\Oracle\bin\javaw.exe" -jar "%User Profile% \iFThgqgAkys\LUOXZqBYDCz.JcfDag"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • ConsentPromptBehaviorAdmin = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • ConsentPromptBehaviorUser = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • PromptOnSecureDesktop = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore
    • DisableConfig = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore
    • DisableSR = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Associations
    • LowRiskFileTypes = ".avi;.bat;.com;.cmd;.exe;.htm;.html;.lnk;.mpg;.mpeg;.mov;.mp3;.msi;.m3u;.rar;.reg;.txt;.vbs;.wav;.zip;.jar;"

Step 4

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\Oracle
  • %User Profile%\iFThgqgAkys - Hidden attribute
  • %User Profile%\iFThgqgAkys\OeQJyiAmqKJ
  • %User Profile%\fUTkALeaTxM
  • %User Profile%\fUTkALeaTxM\DdWDtpinxpf

Step 5

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%\Oracle\{Java Installation Files}
  • %User Profile%\iFThgqgAkys\ID.txt
  • %User Profile%\fUTkALeaTxM\ID.txt
  • %User Temp%\{random string}.reg
  • %User Temp%\_0.{random number 1}.class
  • %User Temp%\_0.{random number 2}.class
  • %System%\test.txt

Step 6

Scan your computer with your Trend Micro product to clean files detected as JAVA_KRYPTIK.NOI. 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.