Security researchers at Comodo have detected a new Zeus trojan variant enhanced with digital signature of its source code to avoid detection from anti-virus systems. This instance presents an interesting feature, it is digitally signed with a stolen digital certificate which belongs to Microsoft Developer. The new Zeus Trojan variant is distributed through infected web page components and via classic phishing email apparently sent by a trusted source including a major bank. More than 200,000 unique malware binaries were discovered in the last couple of years signed with valid digital signatures.”]
Source: https://securityaffairs.co/wordpress/23782/cyber-crime/zeus-trojan-digitally-signed.html