Threat Descriptons



Category :


Type :


Aliases :

Kavala.[variant], Trojan-Downloader:W32/Kavala.[variant], Trojan-Downloader:JS/Kavala.[variant], Trojan:JS/Kavala.[variant], Trojan:VBS/Kavala.[variant], Trojan:W97M/Kavala.[variant]


This detection identifies a variant of the Kavala family of harmful programs, which can contact a remote server and download additional files onto the affected machine or device.


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

Users typically encounter Kavala variants as files that are attached to email messages.

The contents of the email message usually follow typical social engineering patterns - for example, claiming to be a delivery invoice, business-related document or urgent legal summons - to pressure or trick users into running the attached file. Some examples of the message titles used by these emails include:

  • RE: Payment Pending
  • RE:Attachment Shipping Document
  • Tax refund due
  • Statement of Account

The files attached to the email messages are usually deceptively named. Some examples of file names used include:

  • Case_[random_number].zip
  • Refund.doc.js
  • USPS - Missed package delivery.js

Note that some Kavala files use two or more file endings, such as .doc.js; this is a common trick used by malware authors to deceive users about the nature of a file. The actual filetype will vary depending on the specific Kavala variant, and can be any of the following:

  • A Windows executable file (EXE)
  • A JavaScript file (JS)
  • A Microsoft office document file (W97M)
  • A Visual Basic Script (VBS) file

The F-Secure detection which identified the file as a Kavala variant may also indicate its filetype - for example, the detection 'Trojan:JS/Kavala.D' indicates that it is a JavaScript file.

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