Classification

Category :

Malware

Type :

Virus

Aliases :

Cursy

Summary

Most boot sector viruses hide by lowering the amount of RAM visible to the operating system and hiding in the free space they create. EDV is different. It searches for free RAM, starting at E800 and searching downwards. It is also unusual on one other way - on every timer tick it will check if ES or DS point to it - which is possibly the case if a virus-scanning program is running. In this case a HLT instruction is executed - which halts the computer.

Removal

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.

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 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.

Technical Details

Aside from this, the virus is fairly usual. It marks infected diskettes with a "EV" at the end of the boot sector and stores the original boot sector code in the last sector of the last track on 360K diskettes, just like the Yale virus.

One encrypted text string is stored inside the virus code:

That rings a bell,no ? from Cursy