Virus Alert: Maze Ransomware

Type: Ransomware

Severity: - High

The Maze ransomware was initially discovered in May 2019 and recently Cyber

security community has seen a rise in Maze ransomware activities. Maze

ransomware is often delivered via emails or exploit kits such as Fallout

and Spelevo. Fallout and Spelevo exploit kits takes advantage of flaws in

Adobe Flash Player and Microsoft Windows (CVE-2018-8174, CVE-2018-15982,

and CVE-2018-4878). In addition to these, Maze ransomware uses Remote

Desktop Protocol (RDP) and malicious advertisements as its attack vectors.

Maze ransomware uses 2048 bit Rivest-Shamir-Adleman (RSA) and ChaCha20

stream cipher encryption to encrypt files. It appends arbitrary extensions

to the files during the encryption process. The Maze ransomware executes a

“process killer” before starting the encryption processes. Ransomware

terminates target processes mainly debuggers, text editors, and programming

IDEs, databases and languages running on the infected system. Maze

ransomware deletes Shadow Volume Copies twice (pre and post encryption) to

ensure that recovery is not possible. It then changes the user's desktop

wallpaper to a message about the encrypted files and the file name of the

dropped ransom note. The malware tries to make connections to IP addresses

that have been crypted in the binary to send information about the infected

machine.

The ransom note asks the victim to contact the threat actor by email for

the decryption key. An interesting feature of this ransomware is that it

says the ransom amount will be different depending on the type of device.

This is uncommon in this ransomware. Maze operators have used the following

labels to indicate the user's computer type in the wallpaper message:

• Standalone server

• Server in corporate network

• Workstation in corporate network

 • Home computer

• Primary domain controller

• Backup server

• Very valuable for you

Another uncanny characteristic of Maze ransomware has been post compromise

cyber extortion in lieu of stolen data. Failing to pay ransom Maze

operators release stolen data on the Internet.

Indicators of Compromise:

Hashes

SHA256

dee863ffa251717b8e56a96e2f9f0b41b09897d3c7cb2e8159fcb0ac0783611b

SHA1

31c3f7b523e1e4060330958e28882227765c3c5e

SHA256

6345697c16f84d3775924dc17847fa3ff61579ee793a95248e9c4964da586ddi

SHA1

c5938ec75e5b655be84eb94d73adecOf63fbce16

SHA256

5a900fd26a4ece38de5ca319b5893f96c7e9e2450dbac796c12f85b99238ec18

SHA1

1e994b5ac039a1c7612bab93248532bf3ed7e6de

Network IOC’s

Mazedecrypt[.]top

conbase[.]top

mazedecrypt[.]top

condurises[.]xyz

emplementriaton[.]xyz

fantimit[.]xyz

91[.]218.114.11

91[.]218.114.25

91[.]218.114.26

91[.]218.114.31

91[.]218.114.32

91[.]218.114.37

91[.]218.114.38

91[.]218.114.4

91[.]218.114.77

91[.]218.114.79

92[.]63.11.151

92[.]63.15.6

92[.]63.15.8

92[.]63.15.56

92[.]63.17.245

92[.]63.29.137

92[.]63.32.2

92[.]63.32.55

92[.]63.37.100

92[.]63.194.3

92[.]63.194.20

104[.]238.158.250

104[.]168.174.32

104[.]168.198.208

104[.]168.198.230

104[.]168.201.35

104[.]168.201.47

104[.]168.215.54

146[.]0.72.85

149[.]56.245.196

185[.]147.15.22

195[.]123.217.13

Associated File Names

DECRYPT-FILES.html

%ProgramData%\foo.dat

Countermeasures and Best practices for prevention.

• Users are advised to disable their RDP if not in use, if

required, it should be placed behind the firewall and users are to bind

with proper policies while using the RDP.

• Security researchers have seen the Spelevo exploit kit

delivering Maze ransomware. Since Spelevo exploits outdated browser

plugins, users should frequently update their browsers and plugins with the

latest security patch.

• Install ad blockers to combat exploit kits such as Fallout that

are distributed via malicious advertising.

• All operating systems and applications should be kept updated

on a regular basis. Virtual patching can be considered for protecting

legacy systems and networks. This measure hinders cybercriminals from

gaining easy access to any system through vulnerabilities in outdated

applications and software. Avoid applying updates / patches available in

any unofficial channel.

• Restrict execution of Power shell /WSCRIPT in an enterprise

environment Ensure installation and use of the latest version of

PowerShell, with enhanced logging enabled. Script block logging and

transcription enabled. Send the associated logs to a centralized log

repository for monitoring and analysis.

• Establish a Sender Policy Framework (SPF) for your domain,

which is an email validation system designed to prevent spam by detecting

email spoofing by which most of the ransomware samples successfully reaches

the corporate email boxes.

• Application whitelisting/Strict implementation of Software

Restriction Policies (SRP) to block binaries running from %APPDATA% and

%TEMP% paths. Ransomware sample drops and executes generally from these

locations.

• Don't open attachments in unsolicited e-mails, even if they

come from people in your contact list, and never click on a URL contained

in an unsolicited e-mail, even if the link seems benign. In cases of

genuine URLs close out the e-mail and go to the organization’s website

directly through browser.

• Block the attachments of file types,

exe|pif|tmp|url|vb|vbe|scr|reg|cer|pst|cmd|com|bat|dll|dat|hlp|hta|js|wsf

• Consider encrypting the confidential data as the ransomware

generally targets common file types.

• Perform regular backups of all critical information to limit

the impact of data or system loss and to help expedite the recovery

process. Ideally, this data should be kept on a separate device, and

backups should be stored offline.

• Network segmentation and segregation into security zones - help

protect sensitive information and critical services. Separate

administrative network from business processes with physical controls and

Virtual Local Area Networks.