Variants in the Trojan-Downloader:W97M/Downloader family are specially-crafted Microsoft Word document files that, when opened, silently execute a malicious macro embedded in the file. The macro will typically connect to a remote server and download additional files to the affected machine.
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
The vulnerability (or vulnerabilities) leveraged by the specially crafted document file are usually application- or platform-specific; a particular program (or even a specific version of the program) must be installed on the machine in order for the exploit to be effective.
To prevent exploitation of such vulnerabilities, please refer to the application vendor for the latest updates and additional advice.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note You need administrative rights to change the settings.
The detection 'W97M.Downloader.[variant]' identifies malicious macro code embedded in a Microsoft Word document file. This file is usually distributed as an attachment to an email message.
The 'bait' Word document file will typically be crafted to look legitimate and appealing to a user (for example, pretending to be a resume or containing interesting news items or content), so that they are drawn into opening the file.
Once the file is opened, the malicious macro code embedded in the file is launched. Typically, the macro's malicious actions will silently take place in the background, evading the user's notice.
The specific malicious actions performed by the macro will differ by variant, but usually involve downloading and installing additional malicious files onto the affected machine. For an example of a Downloader variant and its behavior, see: