Beware of MalDoc in PDF: A New Polyglot Attack Allowing Attackers to Evade Antivirus

Cybersecurity researchers have called attention to a new antivirus evasion technique that involves embedding a malicious Microsoft Word file into a PDF file. The sneaky method, dubbed MalDoc in PDF by JPCERT/CC, is said to have been employed in an in-the-wild attack in July 2023. "A file created with MalDoc in PDF can be opened in Word even though it has magic numbers and file structure of PDF,"

Cybercriminals Using Polyglot Files in Malware Distribution to Fly Under the Radar

Remote access trojans such as StrRAT and Ratty are being distributed as a combination of polyglot and malicious Java archive (JAR) files, once again highlighting how threat actors are continuously finding new ways to fly under the radar. "Attackers now use the polyglot technique to confuse security solutions that don't properly validate the JAR file format," Deep Instinct security researcher