PeerBlock – Block IP Addresses Of Government Spies Or Evil Hacker Friends [Windows]

Ryan Dube 28-03-2012

block ip addressWhen people want to protect their computer from outside threats, the first thing they usually think of is installing antivirus or anto-malware software. Those applications do an excellent job at blocking known viruses and malware from infecting your PC.  We’ve covered plenty of them here at MUO, like Justin’s list of the 10 best free anti-virus applications The 10 Best Free Antivirus Software No matter what computer you're using, you need antivirus protection. Here are the best free antivirus tools you can use. Read More , or the AV options listed in Aibek’s roundup Roundup: 15 Must-Have Free Software Programs for Your PC Read More of must-have PC apps.


What if antivirus and malware-blockers aren’t enough? What if there is a person or a group of people that are targeting you, but their IP addresses are not blacklisted anywhere that would prompt your AV software to protect you from that traffic?

Here’s an example. I do a lot of research into Chinese corruption, and I have published a lot of articles on the subject. Let’s say that I suspect something is going on, due to odd traffic patterns that I’ve logged with some of my Internet logging utilities. What if this odd traffic comes from criminals that want to hack my PC, as Guy once described Internet Security: How Criminals Hack Other Peoples Computers Read More that criminals can do?

How do you stop select traffic – by blocking specific IP addresses – from accessing your computer? Sure you could mess around with your router settings, but if you want to do it straight from your PC, then you should use a tool like PeerBlock.

Protecting Yourself With PeerBlock

If you think about it, this can really come in handy. Maybe you are on a school dormitory network and you know that a friend is an avid hacker and likes to play practical jokes on you by hacking into your computer. Or maybe you live in a country where government surveillance is the order of business.

With PeerBlock, you can identify known IP addresses or range of addresses and completely block all traffic to and from those locations. Setting it up starts the moment you run the install, when you’re given the option as to what typical types of traffic you want to block.


block ip address

If you select options like spyware or ads, the software will automatically download known IP ranges of spyware culprits, for example.

Please remember, before you start blocking ads, that ads pay for most of the free content that you enjoy online, as Matt Are Ad Blocking Browser Extensions Killing The Internet? One of the reasons for the Internet’s surge in popularity is the cost of most online content – or rather, the lack of cost. That’s not to say the content is free, however. Almost every... Read More  has pointed out. Adding your own custom IP ranges to block is really easy. On one of the setup screens you have the option to create an IP list. You can import these from anywhere on the web, like Name the file and then add that file to your list.

ip block list


In addition to importing known lists, you can also customize your own specific IP ranges. For example, in my case I want to block all traffic from China. To do this, just click “Create List“, give the list a name and also give the file where the range will be stored a name.

ip block list

You will then be presented with a screen where you can specifically name an IP range that you want to block all traffic.

ip block list


Now, I’m not sure what the IP range is for the entire country of China, so I just head on over to and use the Country 2 IP tool to selection a country and get all IP ranges assigned to that region of the world.

how to block ip address

You can just copy and paste those ranges into a text file, named with a .p2p extension and PeerBlock can read in the data. Now you can see on the “Customize Lists” page of the startup Wizard, I now have two files listed that contain all of the customized IP ranges I’m blocking.

how to block ip address


When you finish with your customized lists, you’ll see the main screen where you can monitor everything that’s going on. You’ll see all new IP addresses that are blocked in the central pane, but you can also click on the “View History” button to see all of the activity on PeerBlock while you were away.

how to block ip address

The software will log not only IP addresses that are blocked, but if you enable it, it will also log all IP addresses that were allowed. This is actually a pretty sweet way to see all inbound and outbound traffic from your PC, just to be sure there aren’t any surprises. However, you might want to leave the “Allowed” logging inactive, as it could consume a fair amount of space in a short time.

how to block ip address

The history also lets you select a past date from the calendar on the right to view traffic at some point in the past.

To see if the software was really working, I decided to add just one specific IP range that included the IP of my own blog. You do this by clicking the “List Manager” button and clicking the “Create List” button. Instead of loading a file, you can just manually type in the IP range.

ip block list

Once I enabled the software to block this IP, I opened up a browser window and tried to visit my site. Sure enough, the browser said that it couldn’t access the site, and  you could see that PeerBlock blocked my PC’s traffic to that IP address. Sweet!

block ip address

The block list also alerted me to some traffic being blocked from PeerBlock’s standard malicious IP list that I was unaware of. So it’s obvious the software is very effective at putting an end to any applications or scripts that may have some back-door into your computer.

As you can probably imagine, maintaining IP lists yourself is a bit more complicated than just leaving the job to your antivirus or anti-malware software, but if you know of certain IP ranges of specific people or organizations that you want to block, this is a perfect app to do it.

Give PeerBlock a shot and let us know what you think of it in the comments section below.

Image credit: Orange Computer Mouse via Shutterstock

Related topics: Internet Filters, IP Address.

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  1. Private
    April 1, 2015 at 10:25 am

    Come on guys! a software that has a direct link via forced updates, this does not make us safe it just opens another door!!
    Off-line software without links to the maker is much safer, any software needing a regular interent link is unsafe. My advice don;t share anything you would not want to share, don't communicate in unencrypted area, face book/ social media users are sheep and deserve what is now and coming in the future.

    My interest was windows 10 Paid version and how to block out Microsoft phone home, and decide all the internet coms. Peerblock is no different than Microsoft self made links!

    Remember if any software has to have an internet link from your computer to its computer, don't de surprised about back doors, like Microsoft/ NSA?

    Anyone know of a peerblock type software without phone home updates, please post, security must come first.

  2. J.
    February 14, 2015 at 2:02 am

    i have found peerblock to be useful however recent attacks suggest there is flaws in its protection. Firstly free users can only update their blocklist once every 7 days. Secondly it appears some malwares can indeed tip it over, resulting in all blocks to be over ridden. This is especially evident in previous builds of peerblock that aren't programmed to restrict list updates.
    Thirdly, the default lists protect U.S. namespaces and are limited from protecting other country ip ranges FROM THEIR OWN COUNTRY, where users in these countries can put a country blocklist (blocks all your home country) to show up these ip addresses and decide to allow or restrict them manually. using the permanent allow list. It takes time but coinsiding with your routine eventually you will see which to allow or not with dns lookups on google to determine who it is and wether or not they are malicious by means of aggressiveness in their data collecting techniques by seeking out or creating web forums to attract a healthy LOCAL audience in defence of privacy and protection.

  3. AP
    September 12, 2012 at 9:49 am

    Blocking a entire range of IP but Hackers still find otherways. Well no system is 100% foolproof.

  4. HannibalCat
    August 24, 2012 at 3:58 pm

    Even if it isn't a blanket of security, and nothing is ever 100% effective, it is another level of safety. The lists are updated pretty regularly, but it's a shame the program isn't.

    • spacemaster
      September 8, 2012 at 3:37 pm

      the devs mention that there will be a new version soon.
      they even aim at a nearly total rewrite for version 2.0

      • HannibalCat
        September 8, 2012 at 4:02 pm

        I am filled with joy! Especially with the steps our government is currently taking toward total web surveillance.

  5. Peter
    March 30, 2012 at 1:09 pm

    Love it, love it! Been using it for is, and it's a nice extra line of defense: however flimsy, it works.

    • Ryan Dube
      April 5, 2012 at 12:54 pm

      It does - and definitely should be used in conjunction with other security tools.

  6. Harry M
    March 29, 2012 at 11:06 am

    Have you noticed that PeerBlock prides itself on blocking 1 million IP addresses, which is about one quarter of the iPv4 space ?

    • Keith M
      March 30, 2012 at 2:50 pm

      1 million IP's is definitely not a quarter of the IPv4 space. IP addresses are dotted quads, 4*8 = 32, and 2^32 is around 4 BILLION.

      • Ryan Dube
        April 5, 2012 at 12:55 pm

        Agreed - the calling 1 miillion a quarter of the IPv4 space sounded questionable to me. Thanks for digging deeper Keith.

      • Harry M
        April 17, 2012 at 7:08 pm

        Sorry for the error. Peerblock actually blocks 1,003,795,044 IPs, which is well and truly ONE BILLION, meaning a quarter of the Internet.

  7. Jouni "Rautamiekka" Järvinen
    March 29, 2012 at 9:54 am

    If just Linux had a working one too ...

    • Pat
      March 29, 2012 at 10:40 pm

      Try IPList/IPBlock available at:
      It's free and can use Bluetack's lists.

    • Ryan Dube
      April 5, 2012 at 12:55 pm

      I'm sure Linux must have lots of similar (or better?) tools for this?

      • Jouni "Rautamiekka" Järvinen
        April 5, 2012 at 2:28 pm

        Find me one then !!!

  8. Mick Gill
    March 29, 2012 at 4:59 am

    The only People who really need programs software like this is People who are up to no good. Plus the don't really work as most People have ISPs who log your activity anyway.

    • Richard Bowman
      July 30, 2012 at 4:30 pm

      Yeah and the only people that lock their doors for security are People who are up to no good. Get real Mick Gill.

    • Seamo One
      September 4, 2012 at 3:04 pm

      Wow Mike...
      I think people don't want others to spy on them, because they have the RIGHT TO PRIVACY, or they should anyway.

      Your comment is like saying: "The only people that don't want to be strip-searched, are people that have contraband on them."

      People like you are the reason we're losing our rights at an alarming rate.
      I think you'd feel right at home in places like Cuba, China, or North Korea.

  9. Chris Hoffman
    March 29, 2012 at 1:46 am

    People often use this sort of program (PeerGuardian, etc) because they think it helps protect them while downloading illicit content over BitTorrent.

    Fair warning: It doesn't. It may prevent certain organizations from connecting to you, but they already know your IP address. Your IP address is out there for all to see -- that's just the way BitTorrent works.

    • Ryan Dube
      March 29, 2012 at 2:03 am

      True - although I think what you're pointing out is unrelated to what this app is supposed to do. I know the title is probably a misnomer and implies "blocking your IP" - but that only means blocking traffic to your IP, not actually blocking people from identifying your IP.

      • Chris Hoffman
        March 29, 2012 at 6:53 am

        Yup, but the app in question here has an "anti-p2p organizations"-blocking option, so I thought I'd provide a warning that such options aren't bulletproof protection for p2p-users.

        • corporal_hades
          March 31, 2012 at 2:15 am

          It actually does work, but nothing is 100% and they even say that on the site so I don't know why you would bother saying it other than you are just a hater.

        • Chris Hoffman
          March 31, 2012 at 4:31 am

          I'm not trying to "hate," just trying to address a common misconception.

  10. jasray
    March 29, 2012 at 12:44 am

    It works in a sense, but I don't think the program is actively updated anymore. Last version = 2010. And IP lists (auto)? Who knows!