Cyber Threat Report: 'StopRansomware: Rhysida Ransomware'

This is a joint Cybersecurity Advisory by the Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and the Multi-State Information Sharing and Analysis Center (MS-ISAC). The advisory outlines indicators of compromise (IoCs) and tactics, techniques and procedures (TTPs) associated with Rhysida ransomware attacks. The report states that threat actors have deployed Rhysida ransomware against targets of opportunity across multiple sectors including education, healthcare, manufacturing, information technology, and government. It notes open source reporting on similarities with Vice Society/DEV-0832. In terms of operating model, the advisory notes that researchers have Rhysida using the ransomware-as-a-service (RaaS) approach, with ransomware tools and infrastructure leased to affiliates in a profit-sharing model - ransom money is then divided between the Rhysida operators and the affiliates.

Behavior Prevention on Endpoint

Use capabilities to prevent suspicious behavior patterns from occurring on endpoint systems. This could include suspicious process, file, API call, etc. behavior.

Data Backup

Take and store data backups from end user systems and critical servers. Ensure backup and storage systems are hardened and kept separate from the corporate network to prevent compromise.

Execution Prevention

Block execution of code on a system through application control, and/or script blocking.

Network Intrusion Prevention

Use intrusion detection signatures to block traffic at network boundaries.

Filter Network Traffic

Use network appliances to filter ingress or egress traffic and perform protocol-based filtering. Configure software on endpoints to filter network traffic.

Pre-compromise

This category is used for any applicable mitigation activities that apply to techniques occurring before an adversary gains Initial Access, such as Reconnaissance and Resource Development techniques.

Multi-factor Authentication

Use two or more pieces of evidence to authenticate to a system; such as username and password in addition to a token from a physical smart card or token generator.

User Account Management

Manage the creation, modification, use, and permissions associated to user accounts.

Disable or Remove Feature or Program

Remove or deny access to unnecessary and potentially vulnerable software to prevent abuse by adversaries.

User Training

Train users to be aware of access or manipulation attempts by an adversary to reduce the risk of successful spearphishing, social engineering, and other techniques that involve user interaction.

Restrict Registry Permissions

Restrict the ability to modify certain hives or keys in the Windows Registry.

Application Isolation and Sandboxing

Restrict execution of code to a virtual environment on or in transit to an endpoint system.

Exploit Protection

Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring.

Vulnerability Scanning

Vulnerability scanning is used to find potentially exploitable software vulnerabilities to remediate them.

Privileged Account Management

Manage the creation, modification, use, and permissions associated to privileged accounts, including SYSTEM and root.

Update Software

Perform regular software updates to mitigate exploitation risk.

Network Segmentation

Architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services...

Operating System Configuration

Make configuration changes related to the operating system or a common feature of the operating system that result in system hardening against techniques.

Limit Access to Resource Over Network

Prevent access to file shares, remote access to systems, unnecessary services. Mechanisms to limit access may include use of network concentrators, RDP gateways, etc.

Audit

Perform audits or scans of systems, permissions, insecure software, insecure configurations, etc. to identify potential weaknesses.

Code Signing

Enforce binary and application integrity with digital signature verification to prevent untrusted code from executing.

Antivirus/Antimalware

Use signatures or heuristics to detect malicious software.

Remote Data Storage

Use remote security log and sensitive file storage where access can be controlled better to prevent exposure of intrusion detection log data or sensitive information.

Restrict File and Directory Permissions

Restrict access by setting directory and file permissions that are not specific to users or privileged accounts.

Encrypt Sensitive Information

Protect sensitive information with strong encryption.

Password Policies

Set and enforce secure password policies for accounts.

Application Developer Guidance

This mitigation describes any guidance or training given to developers of applications to avoid introducing security weaknesses that an adversary may be able to take advantage of.

Active Directory Configuration

Configure Active Directory to prevent use of certain techniques; use SID Filtering, etc.

Account Use Policies

Configure features related to account use like login attempt lockouts, specific login times, etc.

Restrict Web-Based Content

Restrict use of certain websites, block downloads/attachments, block Javascript, restrict browser extensions, etc.

Software Configuration

Implement configuration changes to software (other than the operating system) to mitigate security risks associated to how the software operates.