Analysis by: Francis Xavier Antazo
 ALIASES:

Ransom:Win32/Petya.A (Microsoft); Win32/Diskcoder.Petya.A (ESET); Trojan-Ransom.Win32.Petr.a (Kaspersky); Ransom_r.DD (AVG);

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Canal de infecção: Downloaded from the Internet

Known as PETYA crypto-ransomware, this malware displays ransom notes at system startup and overwrites Master Boot Record (MBR). It also abuses the cloud storage service, Dropbox for its infection vector. It deviated from other variants of crypto-ransomware that arrive via email or malicious websites.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

This Trojan 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

Tipo de compactação: 48128 bytes
Tipo de arquivo: DLL
Residente na memória: Yes
Data de recebimento das amostras iniciais: 25 Mar 2016
Carga útil: Encrypts files, Overwrites MBR

Arrival Details

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

NOTES:

This ransomware overwrites the affected system's Master Boot Record (MBR). It encrypts the Master File Table (MFT).

It restarts your system and displays a fake CHKDSK:

  SOLUTION

Mecanismo de varredura mínima: 9.800
Primeiro arquivo padrão VSAPI: 12.438.04
Data do lançamento do primeiro padrão VSAPI: 31 Mar 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Scan your computer with your Trend Micro product to delete files detected as RANSOM_PETYA.D. 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 4

Restore encrypted files from backup.


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