Z-90

Classification

Malware

Virus

W32

Z-90

Summary

Z-90 activates in July and December if an infected file is executed and the time is exactly 09:03. At this time the virus encrypts the DOS boot sector of drive C:, making the PC unbootable (encryption is done by XORing with 16-bit hex value 0903). After this it displays this message:

VIRUS Z-90. JUNIO 95. M
 EXICOSE MURIO TU DISCO
 DUROTU LO PUEDES RE
 VIVIRHAS BAILADO ALGUNA VEZ CON TU NOVIA A LE TENUE LUZ DE LA 		

Z-90 was found in the wild in Brazil in April 1996.

Removal

Automatic action

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.

Suspect a file is incorrectly detected (a False Positive)?

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.

Find out more

Knowledge Base

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User Guide

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Submit a sample

Submit a file or URL for further analysis.

Technical Details

N/A