ALIASES:

Trojan-Downloader.Win32.Deyma.arn (Kaspersky); Troj/Mdrop-IYG (Sophos)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size: 240,640 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 25 Nov 2019

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 adds the following processes:

  • %All Users Profile%\2813b24cf8\vbcoon.exe
  • REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders" /f /v Startup /t REG_SZ /d %All Users Profile%\2813b24cf8

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

It creates the following folders:

  • %All Users Profile%\2813b24cf8

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

Other System Modifications

This Trojan Spy adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.imaadpcm

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msg711

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msgsm610

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msadpcm

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.l3acm

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.imaadpcm
fdwSupport = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.imaadpcm
cFormatTags = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.imaadpcm
aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x00\x11\x00\x00\x00\x14\x00\x00\x00"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.imaadpcm
cFilterTags = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msg711
fdwSupport = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msg711
cFormatTags = "3"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msg711
aFormatTagCache = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msg711
cFilterTags = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msgsm610
fdwSupport = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msgsm610
cFormatTags = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msgsm610
aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x001\x00\x00\x00\x14\x00\x00\x00"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msgsm610
cFilterTags = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msadpcm
fdwSupport = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msadpcm
cFormatTags = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msadpcm
aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x00\x02\x00\x00\x002\x00\x00\x00"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.msadpcm
cFilterTags = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.l3acm
fdwSupport = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.l3acm
cFormatTags = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.l3acm
aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x00U\x00\x00\x00\x1e\x00\x00\x00"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\AudioCompressionManager\DriverCache\
msacm.l3acm
cFilterTags = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
User Shell Folders
Startup = "%All Users Profile%\2813b24cf8"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This Trojan Spy drops the following files:

  • %User Temp%\1532640
  • %All Users Profile%\2813b24cf8\vbcoon.exe:Zone.Identifier
  • %User Temp%\7257440
  • %All Users Profile%\0
  • %All Users Profile%\2813b24cf8\vbcoon.exe

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

Other Details

This Trojan Spy connects to the following possibly malicious URL:

  • http://{BLOCKED}117.46/5vFgnRd4hdDbgS3H/index.php

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.850

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and terminate files detected as TrojanSpy.Win32.ADAMEY.THKBEAI

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache
    • msacm.imaadpcm
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache
    • msacm.msg711
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache
    • msacm.msgsm610
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache
    • msacm.msadpcm
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache
    • msacm.l3acm

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\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.imaadpcm
    • fdwSupport = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.imaadpcm
    • cFormatTags = "2"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.imaadpcm
    • aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x00\x11\x00\x00\x00\x14\x00\x00\x00"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.imaadpcm
    • cFilterTags = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msg711
    • fdwSupport = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msg711
    • cFormatTags = "3"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msg711
    • aFormatTagCache = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msg711
    • cFilterTags = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msgsm610
    • fdwSupport = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msgsm610
    • cFormatTags = "2"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msgsm610
    • aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x001\x00\x00\x00\x14\x00\x00\x00"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msgsm610
    • cFilterTags = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msadpcm
    • fdwSupport = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msadpcm
    • cFormatTags = "2"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msadpcm
    • aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x00\x02\x00\x00\x002\x00\x00\x00"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.msadpcm
    • cFilterTags = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.l3acm
    • fdwSupport = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.l3acm
    • cFormatTags = "2"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.l3acm
    • aFormatTagCache = "\x01\x00\x00\x00\x10\x00\x00\x00U\x00\x00\x00\x1e\x00\x00\x00"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\AudioCompressionManager\DriverCache\msacm.l3acm
    • cFilterTags = "0"

Step 5

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
    • From: Startup = "%All Users Profile%\2813b24cf8"
      To: Startup = ""{random values}""

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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%\1532640
  • %All Users Profile%\2813b24cf8\vbcoon.exe:Zone.Identifier
  • %User Temp%\7257440
  • %All Users Profile%\0
  • %All Users Profile%\2813b24cf8\vbcoon.exe

Step 7

Search and delete this folder

[ 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.
  • %All Users Profile%\2813b24cf8

Step 8

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win32.ADAMEY.THKBEAI. 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 the following Trend Micro Support pages for more information:


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