Petya Ransomeware Attack : What to Do immediately

Petya/Petwrap ransomware

What is Petya Ransomeware do?

Ans: 

Ransomware, Petya does not encrypt files on a targeted system one by one.

Instead, Petya reboots victims computers and encrypts the hard drive's master file table (MFT) and rendering the master boot record (MBR) inoperable, restricting access to the full system by seizing information about file names, sizes, and location on the physical disk.

Petya replaces the computer's MBR with its own malicious code that displays the ransom note and leaves computers unable to boot.

Why it spreads fast?

Ans : Petya ransomware successful in spreading because it combines both a client-side attack (CVE-2017-0199) and a network based threat (MS17-010)

So patch both first!

Affected countries: UK, Ukraine, India, the Netherlands, Spain, Denmark, and others

Behavior:

Encrypts MFT (Master File Tree) tables for NTFS partitions and overwrites the MBR (Master Boot Record) with a custom bootloader that shows a ransom note and prevents victims from booting their computer.

Actions to be taken:

1. Block source E-mail address

wowsmith123456@posteo.net

2. Block domains:

http://mischapuk6hyrn72.onion/

http://petya3jxfp2f7g3i.onion/

http://petya3sen7dyko2n.onion/

http://mischa5xyix2mrhd.onion/MZ2MMJ

http://mischapuk6hyrn72.onion/MZ2MMJ

http://petya3jxfp2f7g3i.onion/MZ2MMJ

http://petya3sen7dyko2n.onion/MZ2MMJ

3. Block IPs:

95.141.115.108

185.165.29.78

84.200.16.242

111.90.139.247

4. Apply patches:

Refer(in Russian): https://habrahabr.ru/post/331762/

5. Disable SMBv1

6. Update Anti-Virus hashes

a809a63bc5e31670ff117d838522dec433f74bee

bec678164cedea578a7aff4589018fa41551c27f

d5bf3f100e7dbcc434d7c58ebf64052329a60fc2

aba7aa41057c8a6b184ba5776c20f7e8fc97c657

0ff07caedad54c9b65e5873ac2d81b3126754aac

51eafbb626103765d3aedfd098b94d0e77de1196

078de2dc59ce59f503c63bd61f1ef8353dc7cf5f

7ca37b86f4acc702f108449c391dd2485b5ca18c

2bc182f04b935c7e358ed9c9e6df09ae6af47168

1b83c00143a1bb2bf16b46c01f36d53fb66f82b5

82920a2ad0138a2a8efc744ae5849c6dde6b435d

myguy.xls EE29B9C01318A1E23836B949942DB14D4811246FDAE2F41DF9F0DCD922C63BC6

BCA9D6.exe 17DACEDB6F0379A65160D73C0AE3AA1F03465AE75CB6AE754C7DCB3017AF1FBD

As of a Kill-switch can be used for #Petya Ransomware. 

i.e. Just create a file "C:\Windows\perfc"

Does this affect you?* 

Though this attack is largely targeting companies, it's important you stay vigilant and take following precautionary measures.

- Always make sure your anti-virus is up-to-date to maximize the protection available to you.

- Don't click too quickly. This attack may be spreading through phishing or spam emails, so make sure you check an email's content for legitimacy. Hover over a link and see if it's going to a reliable URL. Or, if you're unsure about an email's content or the source it came from, do a quick search and look for other instances of this campaign, and what those instances could tell you about the email's legitimacy.

- Do a complete back up. Back up all your PCs immediately. If your machine becomes infected with Petya ransomware, your data could become completely inaccessible. Make sure you cover all your bases and have your data stored on an external hard drive or elsewhere.

- Apply system and application updates.Making sure your operating system is up to date will help contain the spread of this malware.