Analysis by: Cris Nowell Pantanilla

 ALIASES:

Ransom:Win32/WannaCrypt (Microsoft), Trojan-Ransom.Win32.Wanna.c (Kaspersky), Win32/Filecoder.WannaCryptor.D (ESET-NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Ransomware may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 245,760 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 12 May 2017
Payload: Displays windows

Arrival Details

This Ransomware may be dropped by the following malware:

Other System Modifications

This Ransomware changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%Desktop%\@WanaDecryptor@.bmp"

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

NOTES:

This ransomware displays the following ransom window. The language on this window may be changed using different language notes:

It uses the following files to display different languages for the ransom note:

  • {malware path}\msg\m_bulgarian.wnry
  • {malware path}\msg\m_chinese (simplified).wnry
  • {malware path}\msg\m_chinese (traditional).wnry
  • {malware path}\msg\m_croatian.wnry
  • {malware path}\msg\m_czech.wnry
  • {malware path}\msg\m_danish.wnry
  • {malware path}\msg\m_dutch.wnry
  • {malware path}\msg\m_english.wnry
  • {malware path}\msg\m_filipino.wnry
  • {malware path}\msg\m_finnish.wnry
  • {malware path}\msg\m_french.wnry
  • {malware path}\msg\m_german.wnry
  • {malware path}\msg\m_greek.wnry
  • {malware path}\msg\m_indonesian.wnry
  • {malware path}\msg\m_italian.wnry
  • {malware path}\msg\m_japanese.wnry
  • {malware path}\msg\m_korean.wnry
  • {malware path}\msg\m_latvian.wnry
  • {malware path}\msg\m_norwegian.wnry
  • {malware path}\msg\m_polish.wnry
  • {malware path}\msg\m_portuguese.wnry
  • {malware path}\msg\m_romanian.wnry
  • {malware path}\msg\m_russian.wnry
  • {malware path}\msg\m_slovak.wnry
  • {malware path}\msg\m_spanish.wnry
  • {malware path}\msg\m_swedish.wnry
  • {malware path}\msg\m_turkish.wnry
  • {malware path}\msg\m_vietnamese.wnry

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.400.05
FIRST VSAPI PATTERN DATE: 12 May 2017
VSAPI OPR PATTERN File: 13.401.00
VSAPI OPR PATTERN Date: 13 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

Remove the malware/grayware file dropped/downloaded by RANSOM_WCRY.I. (Note: Please skip this step if the threat(s) listed below have already been removed.)

Step 3

Identify and terminate files detected as RANSOM_WCRY.I

[ 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

Reset your Desktop properties

[ Learn More ]

Step 5

Scan your computer with your Trend Micro product to delete files detected as RANSOM_WCRY.I. 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.


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