Anti-establishment group Rubicon (Rouvikonas) targeted the headquarters of Novartis Hellas at the Athens suburb of Metamorphosi early on Sunday.
Members of the group broke the sentry box and windows of the offices with a sledgehammer and threw red paint at 5:15 on Sunday and afterwards they fled.
Rubicon assumed the reasonability of the attack in a post on an anti-establishment website.
Police are conducting an investigation.
