The virus-buster says malicious files buzzing through Webland contain objects such as PowerPoint slides and Excel charts along with Backdoor.Ginwui, a piece of malicious code which opens a back door on the user's computer.
This back-door allows a remote attacker to gather system information and execute code on the attacked machine, the firm warns.
Symantec named the malicious Word documents as Trojan.Mdropper.H. It rates both Backdoor.Ginwui and Trojan.Mdropper.H as Category 1 threats on a scale of 1 to 5 with 5, being the most severe.
It says the attack attempt originated in Asia but is seems to be targeted at specific large organizations so is not spreading as far and as wide as it might otherwise.
It reckons the event illustrates the trend toward zero-day targeted attacks. µ