Attention computer network defenders: The Department of Homeland Security National Cybersecurity & Communications Integration Center and the Federal Bureau of Investigation issued an activity alert today against malware known as SamSam ransomware. The activity alert comes after the Justice Department indicted the Iranian creators of the ransomware, which is also known as MSIL/Samas.A.
Faramarz Shahi Savandi, 34, and Mohammad Mehdi Shah Mansouri, 27, both of Iran, allegedly collected more than $6 million in ransom payments, and are accused of more than $30 million in losses to victims.
“SamSam actors leave ransom notes on encrypted computers,” said the alert. “These instructions direct victims to establish contact through a Tor hidden service site. After paying the ransom in Bitcoin and establishing contact, victims usually receive links to download cryptographic keys and tools to decrypt their network.”
DHS and FBI recommend that users and administrators:
- Audit your network for systems that use RDP for remote communication. Disable the service if unneeded or install available patches. Users may need to work with their technology venders to confirm that patches will not affect system processes.
- Verify that all cloud-based virtual machine instances with public IPs have no open RDP ports, especially port 3389, unless there is a valid business reason to keep open RDP ports. Place any system with an open RDP port behind a firewall and require users to use a virtual private network (VPN) to access that system.
- Enable strong passwords and account lockout policies to defend against brute force attacks.
- Where possible, apply two-factor authentication.
- Regularly apply system and software updates.
- Maintain a good back-up strategy.
- Enable logging and ensure that logging mechanisms capture RDP logins. Keep logs for a minimum of 90 days and review them regularly to detect intrusion attempts.
- When creating cloud-based virtual machines, adhere to the cloud provider’s best practices for remote access.
- Ensure that third parties that require RDP access follow internal policies on remote access.
- Minimize network exposure for all control system devices. Where possible, disable RDP on critical devices.
- Regulate and limit external-to-internal RDP connections. When external access to internal resources is required, use secure methods such as VPNs. Of course, VPNs are only as secure as the connected devices.
- Restrict users’ ability (permissions) to install and run unwanted software applications.
- Scan for and remove suspicious email attachments; ensure the scanned attachment is its “true file type” (i.e., the extension matches the file header).
- Disable file and printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
Savandi and Mansouri are accused of infiltrating the networks of 200 victims, including hospitals, municipalities, and public institutions, the city of Atlanta; the city of Newark; the Port of San Diego; the Colorado Department of Transportation; the University of Calgary in Alberta; the Hollywood Presbyterian Medical Center; the Kansas Heart Hospital, Laboratory Corporation of America Holdings of Burlington, MedStar Health, OrthoNebraska Hospital, in Omaha and Allscripts Healthcare Solutions Inc..