I recommend that you use a different computer to download this tool because sometimes infected machines prohibit the download of Malware removal tools. Save it to an USB Memory Stick and transfer it to the infected machines.
Start your Web Browser and Google for Combofix and only download it from the www.bleepingcomputer.com website as shown in the screenshot below. It’s the first link in the search results.
Now you should see something like in the Screenshot below. Click on the blue box “Download Now @BleepingComputer”
Click on “Save File”
After the download is done start you Explorer by clicking on the icon shown below.
Navigate to your Downloads folder and double click on the Combofix tool as shown below.
For Security purposes Windows asks you if you like to “Run” the downloaded Software. Click on “Run”
Combofix starts with a disclaimer and you have to agree the disclaimer. Click on “I Agree”
After you agreed to the disclaimer the software will extract itself
Combofix looks for running AntiVirus Software like in my example. Some AntiVirus Software cannot be turned off and in that case you just ignore the warning but if you are able to turn it off I highly recommend that you do so. Click on OK
The warning will appears again if you ignored the previous warning. Click on OK again
After the warning Combofix starts to get ready
Combofix informs you that scans may take usually no longer than 10 minutes but on heavily infected machines it might easily double the time. In my experience it will take way longer than that.
The entire scan process will go through 50 Stages.
After going through all 50 Stages Combofix will start removing infected Files and Folders
As soon as deleting the files is done Combofix generates a report.