Microsoft security experts believe that the Silver framework is actively used by cyberattackers to carry out intrusion campaigns.
Team Cymru observed a steady increase in detected Silver samples over Q1 of 2022 and shared some case studies. Silver can be used to compromise a target, deploy one or more implants within different endpoints or servers belonging to a compromised network, and use the framework for command and control C2 interactions.
Silver is an open-source cross-platform adversary emulation/red team framework that can be used by organizations of any size to perform security testing. Silver’s implants support C2 over Mutual TLS (mTLS), WireGuard, HTTP (S), and DNS. Silver’s implants are dynamically compiled with per-binary asymmetric encryption keys.
The framework is written in the Go programming language, also known as Golang, a language that supports cross-platform functionality.
To protect against malicious exploitation of the framework by attackers, Microsoft has provided queries that can be executed within the Microsoft 365 Defender portal. This will help to detect official, non-customized Silver codebases. Microsoft has also released JARM hashes. JARM is an active Transport Layer Security (TLS) server fingerprinting tool.
Organizations are advised to use MFA on any internet-enabled systems or services, especially for RDP or VPN connections. While all systems should be patched and up to date, user privileges should also be limited, and administrative privileges should only be granted to employees who really need them.
The sources for this piece include an article in TechRepublic.
