Attackers have a new obfuscation technique that uses the OpenDocument file format for sneaking payloads past antivirus software. Cisco Talos researchers Warren Mercer and Paul Rascagneres said some AV engines and system sandboxes do not handle these ODT file formats with the appropriate method so they become missed in some instances. In the documented cases where ODT files were used successfully in attacks the majority of the incidents involved Microsoft Office, while OpenOffice and LibreOffice were targeted to a lesser degree.
Source: https://threatpost.com/hackers-turn-to-opendocument/148817/

