Analysis by: Janus Agcaoili
ALIASES:

Trojan-Ransom.Win32.Wanna.y (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via network shares, Downloaded from the Internet, Dropped by other malware

This Worm 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

File Size: 4,952,064 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 12 May 2017
Payload: Drops files

Arrival Details

This Worm may arrive via network shares.

It 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 Worm drops and executes the following files:

  • %Windows%\lsasvs.exe <- detected as TROJ_WCRY.H, installs and executes the Tor client (lsass.bin) and encryptor module (taskhcst.exe)

Autostart Technique

This Worm adds and runs the following services:

  • ServiceName: shcservice
    DisplayName: Windows SHC Service.
    ImagePath: cmd.exe /c “net share C$=C:\”. <- This makes the C drive of the remote machine shared
  • ServiceName: WUpdator
    DisplayName: Windows Updator
    ImagePath: C:\Windows\svchost.exe -> This will execute its copy in the remote machine

Propagation

This Worm uses the following file names for the copies it drops into shared networks:

  • %Windows%\svchost.exe

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

It uses the following user name and password to gain access to password-protected shares:

  • administrador
  • admin
  • Administrator
  • abcd
  • cowboy
  • sparky
  • asdfgh
  • secret
  • bigdog
  • yellow
  • diamond
  • richard
  • patrick
  • chelsea
  • martin
  • cheese
  • golfer
  • matthew
  • merlin
  • austin
  • fucker
  • taylor
  • corvette
  • summer
  • hammer
  • heather
  • ginger
  • nicole
  • thunder
  • sexy
  • computer
  • freedom
  • biteme
  • orange
  • amanda
  • hello
  • ashley
  • yankees
  • dallas
  • william
  • silver
  • maggie
  • joshua
  • access
  • daniel
  • pepper
  • asshole
  • jessica
  • sunshine
  • love
  • michelle
  • andrew
  • charlie
  • george
  • hockey
  • killer
  • batman
  • fuck
  • soccer
  • robert
  • tigger
  • thomas
  • buster
  • ranger
  • trustno1
  • fuckyou
  • hunter
  • fuckme
  • harley
  • jordan
  • jennifer
  • shadow
  • michael
  • mustang
  • welkome
  • bumble
  • pussy
  • monkey
  • root
  • angel
  • solo
  • asdfg
  • asdf
  • qwer
  • starwars
  • qwertyuiop
  • princess
  • baseball
  • football
  • letmein
  • superman
  • login
  • test
  • pass
  • passwd
  • master
  • dragon
  • abc123
  • server
  • 1qaz2wsx
  • welcome
  • qwerty
  • passw0rd
  • password
  • p@ssw0rd
  • !@#$%^&*()
  • !@#$%^&*(
  • !@#$%^&*
  • !@#$%^&
  • !@#$%^
  • !@#$%
  • !@#$
  • abcd1234
  • 123456!
  • 12345!
  • 1234!@#$
  • 1q2w3e4r!
  • 1q2w3e4!
  • 1q2w3e!
  • 1q2w3e4r
  • 1q2w3e4
  • 1q2w3e
  • 121212
  • 666666
  • 6969
  • 696969
  • 123123
  • 654321
  • 4321
  • 54321
  • 1111
  • 111111
  • 1234567890
  • 1234567
  • 1234
  • 123456789
  • 12345
  • 12345678
  • 123456

Dropping Routine

This Worm drops the following files:

  • %Windows%\lsass.bin <- contains the Tor Client and its components
  • %Windows%\fff <- dropped as system file with 0 bytes
  • %Windows%\taskhcst.exe <- main encryptor module, detected as Ransom_WCRY.H

Other Details

This Worm does the following:

  • It scans the following to check for open port 445:
    • Hosts on the Local Area Network
    • Randomly-generated IP address over the Internet
  • If it finds a host either on the LAN/Internet with open port 445, it attempts to remotely create a service (via IPC$ share) and drop its copy in the remote machine by brute-forcing access in the file sharing

  SOLUTION

Minimum Scan Engine: 9.850

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

Disable this malware service

[ Learn More ]
  •  shcservice
    WUpdator

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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

    TROJ_WCRY.H
    Ransom_WCRY.H

Step 6

Search and delete this file

[ Learn More ]
There may be some files 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. %Windows%\lsass.bin
%Windows%\fff

Step 7

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


Did this description help? Tell us how we did.