OTX Threat: Not very gentlemanly: Analyzing a zero-day exploit used to disable targets' EDRs

The Gentlemen ransomware group, which emerged in July 2025, employed a zero-day vulnerability in a bring-your-own-vulnerable-driver (BYOVD) attack to disable endpoint detection and response systems. During an incident investigated in early April, the group leveraged an obscure third-party driver named ktapi.sys from Kontron to bypass security protections. The sophisticated exploit chains multiple