Why a recent supply-chain attack singled out security firms Checkmarx and Bitwarden

A recent supply-chain attack singled out security firms Checkmarx and Bitwarden by deploying fake updates from a compromised third-party vendor, breaching systems designed to protect millions of users. The attackers used malicious code hidden in a routine update, affecting 12,000 customers within 48 hours before detection. This operation was 40% more efficient than the average supply-chain attack, per Mandiant's 2025 report, because it targeted defenders directly. The #8 seashells case may grab headlines, but this strike on security vendors poses a practical threat: Checkmarx lost 8% of its stock value in a single day after disclosure. Bitwarden's password manager data for 2,000 enterprise clients was exposed, though no master passwords were compromised. The motive appears to be strategic — disabling the watchdogs.