Microsoft has now confirmed signing a malicious driver being distributed within gaming environments. This driver, called "Netfilter," is in fact a rootkit that was observed communicating with Chinese command-and-control (C2) IPs. G Data malware analyst Karsten Hahn first took notice of this event last week and was joined by the wider infosec. community in tracing and analyzing the malicious drivers bearing the seal of Microsoft. This incident has once again exposed threats to software supply-chain security, except this time it stemmed from a weakness in Microsoft's code-signing process. [...] "Since Windows Vista, any code that runs in kernel mode is required to be tested and signed before public release to ensure stability for the operating system." "Drivers without a Microsoft certificate cannot be installed by default," states Hahn. [...] According to Microsoft, the threat actor has mainly targeted the gaming sector specifically in China with these malicious drivers, and there is no indication of enterprise environments having been affected so far. Microsoft has refrained from attributing this incident to nation-state actors just yet. Falsely signed binaries can be abused by sophisticated threat actors to facilitate large-scale software supply-chain attacks. The multifaceted Stuxnet attack that targeted Iran's nuclear program marks a well-known incident in which code-signing certificates were stolen from Realtek and JMicron to facilitate the attack. This particular incident, however, has exposed weaknesses in a legitimate code-signing process, exploited by threat actors to acquire Microsoft-signed code without compromising any certificates. Continua, con qualche informazione più tecnica e link ad approfondimenti, su http://web.archive.org/web/20210708084042/https://www.bleepingcomputer.com/n... Giacomo