Microsoft security software detects and removes this threat.

This threat can infect your PC if it is running vulnerable software, including:

  • Adobe Flash Player version 10 update 3 and earlier, and version 11 update 5 and earlier.
  • Silverlight version 5 and earlier.

If your PC has vulnerable software this threat can download other malware, including Win32/Miuref.

You might get an alert about this threat even if you're not using a vulnerable software. This is because we detect when a website tries to use the vulnerability, even if it isn't successful.

What to do now

The following free Microsoft software detects and removes this threat:

Even if we've already detected and removed this particular threat, running a full scan might find other malware that is hiding on your PC.

You can also visit the Microsoft virus and malware community for more help.

Update Java

Make sure you install all available Java updates.

You should remove older versions of Java, as keeping old and unsupported versions of Java on your PC is a serious security risk:

If you continue to get alerted about this threat, deleting your temporary Java files can help:

It's also important to keep your other software up to date:

Threat behavior

Exploit:HTML/Fiexp.A is a detection for the landing page of the exploit kit known as Fiesta. We have observed the landing page at the following hosts:


We have seen it exploit the following vulnerabilities:

  • CVE-2013-0634 (Adobe Flash Player version 10 update 3 and earlier, and version 11 update 5)
  • CVE-2013-0074 (Silverlight version 5 and earlier)

If successful this threat can download and run other malware, including:


Alerts from your security software may be the only symptom.


Alert level: Severe
First detected by definition:
Latest detected by definition: and higher
First detected on: Mar 19, 2014
This entry was first published on: Mar 06, 2014
This entry was updated on: Apr 02, 2014

This threat is also detected as:
  • JS/Crypted.EY! (Command)
  • Mal/ExpJS-S (Sophos)
  • Fiesta exploit kit (other)