Ransom_Crowti.R002C0CJF19

October 15, 2019
 ALIASES:

Ransom:Win32/Crowti (Microsoft); Packed-EW!C5B99308A63D (McAfee); Ransom.Cryptodefense (Symantec); Troj/Ransom-BDH (Sophos); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

364,545 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

15 Oct 2019

Arrival Details

This Ransomware 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 Ransomware drops the following copies of itself into the affected system:

  • %System Root%\32360776\32360776.exe
  • %Application Data%\32360776.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • %Windows%\syswow64\svchost.exe -k netsvcs
  • vssadmin.exe Delete Shadows /All /Quiet
  • bcdedit /set {default} recoveryenabled No
  • bcdedit /set {default} bootstatuspolicy ignoreallfailures

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
3236077 = "%System Root%\32360776\32360776.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
*236077 = "%System Root%\32360776\32360776.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
32360776 = "%Application Data%\32360776.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
*2360776 = "%Application Data%\32360776.exe"

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows NT\CurrentVersion\
SystemRestore
DisableSR = "1"

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run\Windows Defender

Dropping Routine

This Ransomware drops the following files:

  • %System Root%\32360776
  • %User Startup%\32360776.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

Other Details

This Ransomware connects to the following possibly malicious URL:

  • http://{BLOCKED}rnalip.com/raw
  • http://{BLOCKED}welry.com/{random path}?f=tffhkw9ozx
  • http://{BLOCKED}lserwa.com/wp-content/plugins/wp-db-backup-made/a.php?p=tffhkw9ozx
  • http://{BLOCKED}a.pl/{random path}?p=tffhkw9ozx
  • http://{BLOCKED}n.ru/{random path}?u=tffhkw9ozx
  • http://{BLOCKED}imagenes.com/{random path}?g=tffhkw9ozx
  • http://dag.{BLOCKED}c.uab.es/{random path}?e=tffhkw9ozx
  • http://{BLOCKED}a.com/{random path}?o=tffhkw9ozx
  • http://{BLOCKED}ron.com/{random path}?k=tffhkw9ozx
  • http://{BLOCKED}g-girl.org/{random path}?b=tffhkw9ozx
  • http://madarco.{BLOCKED}m.br/site/wp-content/themes/twentyeleven/e.php?v=tffhkw9ozx
  • http://{BLOCKED}n.cz/{random path}?p=tffhkw9ozx
  • http://{BLOCKED}ental.com/{random path}?f=tffhkw9ozx
  • http://www.{BLOCKED}ental.com/{random path}?f=tffhkw9ozx
  • http://{BLOCKED}pa.ro/wp-content/themes/twentythirteen/a.php?z=tffhkw9ozx
  • http://{BLOCKED}nes.com/wp-content/themes/twentyeleven/a.php?z=tffhkw9ozx
  • http://{BLOCKED}tech.pl/wp-content/themes/twentyeleven/d.php?q=tffhkw9ozx
  • http://{BLOCKED}n.com/{random path}?o=tffhkw9ozx
  • http://kbf.{BLOCKED}m.pl/{random path}?v=tffhkw9ozx
  • http://{BLOCKED}welry.com/{random path}?u=6r51rrzfe82
  • http://{BLOCKED}lserwa.com/wp-content/plugins/wp-db-backup-made/a.php?q=6r51rrzfe82
  • http://{BLOCKED}apartman.hu/de/wp-content/plugins/wp-db-backup-made/e.php?g=6r51rrzfe82
  • http://{BLOCKED}a.pl/{random path}?x=6r51rrzfe82
  • http://{BLOCKED}r.es
  • http://{BLOCKED}ip.com
  • http://confeitariasaborearte.{BLOCKED}m.br
  • http://{BLOCKED}entacademy.com
  • http://{BLOCKED}olar.pl
  • http://{BLOCKED}ic.ro
  • http://{BLOCKED}c.pl
  • http://{BLOCKED}e.pl
  • http://paternidadresponsable.{BLOCKED}m.mx
  • http://{BLOCKED}p.pl
  • http://www.{BLOCKED}n.com
  • http://{BLOCKED}ty.pl
  • http://{BLOCKED}ia.com
  • http://monki.{BLOCKED}o.pl
  • http://{BLOCKED}ot.pl
  • http://ebj.{BLOCKED}m.pl
  • http://unikone.{BLOCKED}z.pl
  • http://cislog.{BLOCKED}m.pl
  • http://memorybits.{BLOCKED}o.uk
  • http://{BLOCKED}deoyunlari.org

It deletes itself after execution.

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

Restart in Safe Mode

[ Learn More ]

Step 3

Identify and terminate files detected as Ransom_Crowti.R002C0CJF19

[ 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 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
    • 3236077 = "%System Root%\32360776\32360776.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • *236077 = "%System Root%\32360776\32360776.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • 32360776 = "%Application Data%\32360776.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • *2360776 = "%Application Data%\32360776.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\SystemRestore
    • DisableSR = "1"

Step 5

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.
  • %System Root%\32360776
  • %User Startup%\32360776.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom_Crowti.R002C0CJF19. 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.

Step 7

Restore encrypted files from backup.

Step 8

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_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
    • Windows Defender


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