Why did antivirus not pick bespoke Trojan?

Antivirus software may not detect bespoke Trojans due to their customized nature, which allows them to evade signature-based detection methods. These unique malware variants are often crafted to exploit specific vulnerabilities or use novel obfuscation techniques, making them harder for traditional antivirus solutions to recognize. Additionally, bespoke Trojans can be designed to mimic legitimate software behavior, further complicating detection efforts. As a result, organizations may need to implement advanced security measures, such as behavior-based detection and threat intelligence, to identify and mitigate these threats effectively.