Test your AV with a sample .js javascript file. Will your AV let you run it?

[+Warwagon MVC]

After the news story on the front page about New ransomware variant coded entirely on Javascript, exploits macros

 

I decided to do a test.

 

The EICAR anti-malware test file was developed by the European Institute for EICAR. The EICAR test file is a legitimate DOS program that is detected as malware by anti-virus software. When the test file runs successfully (if it is not detected and blocked), it prints the message "EICAR-STANDARD-ANTIVIRUS-TEST-FILE!".

X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*

Pasted it into notepad and saved it as hello.js

 

Then double clicked on Hello.js on the desktop and got this prompt

 

 

So try it yourself and post your result of your Antivirus.

 

if it runs you should see a Microsoft JScript Compilation error

 

 

 

 

[purrcher]

Avast free ran the Hello.js file.

I might setup a few VMs to check other popular options.

[DaveLegg Developer]

I imagine most AV software wouldn't care, as it's clearly not malicious code that's going to trigger any of their heuristic scanning. There's not going to be any signatures that match such a simple and harmless script either. This is basically a useless test.

[+Warwagon MVC]

  On 21/06/2016 at 18:26, DaveLegg said:

I imagine most AV software wouldn't care, as it's clearly not malicious code that's going to trigger any of their heuristic scanning. There's not going to be any signatures that match such a simple and harmless script either. This is basically a useless test.

Expand  

Because the AV is relying on it's signatures to detect what's going to run inside the .js file, as a good rule of thumb an AV should stop and prompt you if you are sure you want to run the JS file.

[er0n]

A good AV will not detect this file as malicious. The file is NOT malicious, so any prompts are false positives, which confuse users and affect productivity in the workplace.

 

This thread should be deleted to avoid confusion.

[er0n]

  On 21/06/2016 at 18:24, purrcher said:

Avast free ran the Hello.js file.

I might setup a few VMs to check other popular options.

Expand  

Don't waste your time!

 

[+Warwagon MVC]

 

  On 21/06/2016 at 18:45, er0n said:

A good AV will not detect this file as malicious. The file is NOT malicious, so any prompts are false positives, which confuse users and affect productivity in the workplace.

 

This thread should be deleted to avoid confusion.

Expand  

I kind of like the fact that my AV "Secureaplus" prompts me about any js file, period.  If the AV you've described hasn't gotten the definition file yet, it allows it to run,. When are regular users needing to run js files on the desktop?

[er0n]

  On 21/06/2016 at 18:51, warwagon said:

 

I kind of like the fact that my AV "Secureaplus" prompts me about any js file, period.  If the AV you've described hasn't gotten the definition file yet, it allows it to run,. When are regular users needing to run js files on the desktop?

Expand  

That's not the point.

 

MOST people aren't security-savvy enough to know whether they should allow the file to run or not. Most scripts will be legitimate so the user will have to approve them in order to do what they want. They end up with alert-fatigue and will probably just approve everything.

 

MOST AVs have the ability to configure detection prompts for scripts or even unknown files.

 

Your posts suggests that your hello world script is a legitimate test for the effectiveness of an AV. Which it is certainly not!

 

Edit: And if you're convinced that users don't need to run these scripts, just disable the ability to execute them in Windows https://technet.microsoft.com/en-us/library/ee198684.aspx

[purrcher]

  On 21/06/2016 at 18:50, er0n said:

Don't waste your time!

 

Expand  

I actually decided to use the eicar test text instead and see what would happen. That was always caught as soon as I saved it as a .js file.

[+Warwagon MVC]

  On 21/06/2016 at 20:04, purrcher said:

I actually decided to use the eicar test text instead and see what would happen. That was always caught as soon as I saved it as a .js file.

Expand  

Great! Good job!

[xendrome]

  On 21/06/2016 at 20:04, purrcher said:

I actually decided to use the eicar test text instead and see what would happen. That was always caught as soon as I saved it as a .js file.

Expand  

http://www.eicar.org/download/eicar.com.txt

[+Warwagon MVC]

  On 21/06/2016 at 20:09, xendrome said:

http://www.eicar.org/download/eicar.com.txt

Expand  

 

[purrcher]

  On 21/06/2016 at 20:09, xendrome said:

http://www.eicar.org/download/eicar.com.txt

Expand  

basically. What I did was I opened Notepad++ and pasted the sniped from http://www.eicar.org/86-0-Intended-use.html and then tried saving it as a ,js file.

[Obi-Wan Kenobi]

This is well known by all antivirus products, and is nothing new. Of course they're going to catch it! If they didn't, then I'd be worried! Therefore, this thread is like a midget without an index finger....short and pointless.

[Yorak]

Bitdefender Antivirus Plus 2016 zapped it from orbit.

[The Evil Overlord]

Yup

Mine didn't let me run it

deleted the file before I could even save it

 

[Rippleman]

I forgot to save it as a .js and saved it as a simple .txt and 360 total security still locked it down.

[Hum]

I got this !

[jnelsoninjax]

Running Kaspersky Total Security, and the moment I save the file, it disappears, no error, but I tried it three times with explorer open in the background and it seems kaspsersky deleted it right away.

[Gerowen]

ClamAV on Linux picks it up.  If I recall correctly though, the EICAR test file should get picked up by just about any antivirus regardless of what you name it or what extension you give it, as long as that string of text is the first line of the file.