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
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:
Associated File Names
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
• 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,
• 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.