Trojan-Downloader:JS/MalJas

Classification

Category :

Malware

Type :

Trojan-Downloader

Aliases :

Trojan-Downloader:JS/MalJas

Summary

Trojan-Downloader:JS/MalJas identifies obfuscated JavaScript files.

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

Trojan-Downloader:JS/MalJas identifies JavaScript files that have been obfuscated - that is, it contains code that has been written to be difficult for other programmers to read or understand.

Obfuscation may be legitimately used by software developers to reduce the size of the program file, or to increase security. It is however also widely used by malware authors to make it harder for security researchers to reverse-engineer a suspect program's code in order to identify what harmful actions it takes.

For this reason, a file that has been obfuscated is flagged for further examination to make sure it is not deliberately harmful.