PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Potentially Unwanted Application 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: 379,048 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 16 Jun 2020

Arrival Details

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

Other System Modifications

This Potentially Unwanted Application deletes the following files:

  • %User Temp%\sdjarfile.txt

(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).)

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
Mode = "6"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
LogicalViewMode = "2"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
FFlags = "1092616257"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
IconSize = "48"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
ColInfo = "{random characters}"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
Sort = "{random characters}"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
GroupView = "0"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
GroupByKey:FMTID = "{{GUID}}"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
GroupByKey:PID = "0"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
GroupByDirection = "1"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
FFlags = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CIDSave\Modules\GlobalSettings\
ProperTreeModuleInner
ProperTreeModuleInner = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Modules\NavPane
ExpandedState = "{random characters}"

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\Bags\
19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}\
GroupCollapseState

Dropping Routine

This Potentially Unwanted Application drops the following files:

  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_sr.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_1024.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_96.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_256.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_idx.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_32.db

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

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

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\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • Mode = "6"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • LogicalViewMode = "2"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • FFlags = "1092616257"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • IconSize = "48"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • ColInfo = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • Sort = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • GroupView = "0"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • GroupByKey:FMTID = "{{GUID}}"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • GroupByKey:PID = "0"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • GroupByDirection = "1"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • FFlags = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CIDSave\Modules\GlobalSettings\ProperTreeModuleInner
    • ProperTreeModuleInner = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Modules\NavPane
    • ExpandedState = "{random characters}"

Step 3

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.
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_sr.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_1024.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_96.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_256.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_idx.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_32.db

Step 4

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.Softonic.AI. 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:

Step 5

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Temp%\sdjarfile.txt

Step 6

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags\19\ComDlg\{5C4F28B5-F869-4E84-8E60-F11DB97C5CC7}
    • GroupCollapseState


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