Zimuse is a family of worms that performs destructive overwrite of the Master Boot Record of disk drives on the infected system.
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.
Zimuse.A arrives on the system either as a standalone file (possibly from a malicious download or email) or by infected removable devices (e.g., USB sticks).
When executed, it will display a fake WinZip dialog box (see image below). This dialog box is a sham. Regardless of the user's subsequent interaction, the worm has already infected the system.
The following file operations will be performed on the system:
Uses registry launchpoints to ensure its components run or are loaded as services on every startup (see below).
Creates these keys:
Sets these values:
After a certain time period from the initial infection, the worm will infect removable drives inserted into the system by dropping a copy of itself named zipsetup.exe and an autorun.inf file as show below:
[autorun] shellexecute=zipsetup.exe /H
After a further period of dormancy, the worm will trigger its payload, which overwrites the Master Boot Record of available drives on the system, and effectively crippling the file system and rendering data on the disk inaccessible except with specialist tools. The following dialog box will be displayed:
On next boot the system will be unbootable.