RANSOM_STUPALOISA.A

August 09, 2017
 Analysis by: Ryan Paolo Maglaque
 ALIASES:

Mal/MSILRnsm-A(Sophos)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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 encrypts files found in specific folders.

  TECHNICAL DETAILS

File Size:

1,453,056 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

14 Jul 2017

Payload:

Displays windows, Encrypts files

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.

Other Details

This Ransomware does the following:

  • Displays the following window as ransom note:

  • Requires the password CREATEDBYMR403FORBIDDEN to decrypt files

  • Displays the following window after using the password:

  • Displays the message box after decryption:

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • D:\

It appends the following extension to the file name of the encrypted files:

  • .aloisa

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.540.07

FIRST VSAPI PATTERN DATE:

18 Jul 2017

VSAPI OPR PATTERN File:

13.541.00

VSAPI OPR PATTERN Date:

19 Jul 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

Scan your computer with your Trend Micro product to delete files detected as RANSOM_STUPALOISA.A. 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 3

Restore encrypted files from backup.


Did this description help? Tell us how we did.