Masscan on Windows: There Is No Official Binary — Here Is How to Build and Run It

Hi folks! Sooner or later every Windows user who hears about Masscan does the same thing: opens Google, types “masscan windows download”, and starts looking for an .exe. And that is exactly where the trouble begins, because the honest answer to that search is not what most people expect.

Let’s go through it properly: what the project actually ships, why there is no official binary waiting for you, how to build one yourself with either Visual Studio or MinGW, the one DLL you absolutely need, and the surprising area where Windows is genuinely better than Linux for scanning. All of it checked against the current repository, not from memory.

Table of Contents

• Is There an Official Masscan Binary for Windows?
• Why Random .exe Downloads Are a Bad Idea Here
• Building with Visual Studio
• Building with MinGW
• The Missing Piece: wpcap.dll
• Your First Scan on Windows
• Where Windows Actually Wins: Banners
• Where Windows Loses: Raw Speed
• WSL2, Docker and Other Ways Out
• Conclusion

Is There an Official Masscan Binary for Windows?

No. There isn’t one, and there hasn’t been for years.

We checked the project’s releases directly through the GitHub API. The newest release is 1.3.2, published on 31 January 2021, and it carries no attached files beyond the source archives that GitHub generates automatically. There is no masscan.exe, no zip with a compiled build, nothing.

There is a bin/ directory in the repository, and its name gets people’s hopes up. It contains exactly one file — a .gitignore, sixteen bytes. It is where the build output lands after you compile, not where a ready binary lives.

So if you have been searching for an official download link and finding nothing, you were not looking in the wrong place. It genuinely does not exist. The project expects you to compile it.

Why Random .exe Downloads Are a Bad Idea Here

Search results are full of sites offering “masscan.exe, ready to run”. Think about what such a binary is: a program that sends raw packets, needs administrator rights, and talks to a low-level packet driver. That is a near-perfect disguise for something unpleasant, and you have no way to verify what was compiled into it.

If you do end up using a third-party build, at the very least prefer one whose source and build pipeline you can inspect, and run it somewhere disposable first. Building it yourself takes about ten minutes and removes the entire question.

Building with Visual Studio

The repository ships a Visual Studio solution. The README puts it plainly: “Windows w/ Visual Studio: use the VS10 project”. Inside vs10/ you will find masscan.sln, masscan.vcxproj and the matching filters file.

git clone https://github.com/robertdavidgraham/masscan
cd masscanvs10

Then open masscan.sln, let Visual Studio retarget the project to your installed toolset when it offers to, pick the Release configuration and x64 platform, and build. The resulting executable lands under the project’s output directory.

The project name says VS10 because it was created for Visual Studio 2010, but the retarget dialog in modern versions handles it fine — the code itself is plain C with very few dependencies.

Building with MinGW

If you would rather not install Visual Studio, MinGW works and the instruction is refreshingly short — the README says “Windows w/ MinGW: just type make“:

git clone https://github.com/robertdavidgraham/masscan
cd masscan
make

The build produces the binary in masscan/bin. Since the source is many small C files, a parallel build helps a lot:

make -j4

One thing that will save you an evening: Cygwin does not work. That is not a rumour, it is stated in the project’s own build notes — “Windows w/ cygwin: won’t work”. Use MinGW or Visual Studio.

The Missing Piece: wpcap.dll

You compiled it, you run it, and it immediately complains that it cannot load wpcap.dll. This is the single most common “it doesn’t work on Windows” report, and it is not a bug.

Masscan loads the packet library at runtime. In src/rawsock.c the code literally calls LoadLibraryA("wpcap.dll") and prints couldn't load wpcap.dll when that fails. No DLL, no packets — the scanner has no way to put frames on the wire.

That DLL comes from a packet capture driver. Install Npcap and tick the WinPcap API-compatible mode option during setup, which is what provides wpcap.dll. The older WinPcap works too, but it has been unmaintained for years and does not love modern Windows.

After installing, open a fresh terminal — the loader looks up the DLL when the process starts, so a shell opened before the installation will keep failing.

Your First Scan on Windows

Run the terminal as Administrator — raw packet access is not available to a normal user. Then start small:

masscan.exe 203.0.113.10 -p80,443 --rate 100

If nothing at all comes back, check the adapter list first — on a laptop with VPN clients and virtual switches, Masscan may well pick the wrong interface:

masscan.exe --iflist

Then point it at the right one explicitly, and write results somewhere useful:

masscan.exe 203.0.113.0/24 -p80,443 --rate 1000 -e "Ethernet" -oJ results.json

Scan only what you are authorised to scan. On Windows in particular, people tend to test against their home network first — that is fine, your own LAN is yours.

Where Windows Actually Wins: Banners

Here is the part nobody mentions in the download-hunting posts. Banner grabbing is easier on Windows.

Masscan carries its own TCP stack. On Linux, when a target replies to a probe, the kernel sees a packet for a connection it never opened and helpfully answers with a RST — tearing down the session before any banner arrives. That is why every Linux banner-grabbing guide involves either a dedicated --source-ip outside the host’s own address or an iptables rule dropping outgoing resets.

Windows does not send those RST packets, so none of that dance is required. The project’s own documentation says as much: on Windows neither of those techniques is necessary. You can simply run:

masscan.exe 203.0.113.0/24 -p80,443 --banners --rate 1000 -oJ banners.json

The advice still stands to give Masscan its own IP address when you can — it is designed to work best that way — but on Windows it is a preference, not a prerequisite.

Where Windows Loses: Raw Speed

Now the trade-off, and it is a big one. The project documents the difference bluntly: on Windows, or inside a VM, Masscan pushes around 300,000 packets per second. On bare-metal Linux it does about 1.6 million.

That is more than a fivefold gap, and it comes from how packets reach the wire, not from the scanner’s logic. For a subnet or a few thousand hosts it does not matter. For an internet-wide sweep it decides whether your scan takes an hour or most of a day.

So the honest rule of thumb: Windows for local work, targeted sweeps and banner grabbing; Linux when volume is the point.

WSL2, Docker and Other Ways Out

If you are on Windows but want Linux behaviour, you have options — each with a catch.

• WSL2 — you get the normal Linux build with a plain apt install masscan, but you also inherit NAT’d networking, so raw packet behaviour and source addressing need attention before results make sense.
• Docker Desktop — same story, plus you will need --cap-add=NET_RAW or host networking for the container to send raw frames at all.
• A cheap Linux VPS — often the pragmatic answer: full speed, a clean public IP, and nothing on your workstation.

Whichever you pick, remember that the network in between matters as much as the host: consumer routers and VM hypervisors will happily become the bottleneck long before Masscan does.

Conclusion

To sum it up: there is no official Masscan binary for Windows and there has not been one since the 1.3.2 release in January 2021. Build it yourself from the vs10 solution or with MinGW, install Npcap in WinPcap-compatible mode so wpcap.dll exists, run your shell as Administrator, and check --iflist when packets seem to vanish.

In exchange you get easier banner grabbing than Linux offers, at roughly a fifth of the packet rate. That trade is fine for local and targeted work, and painful for anything internet-scale.

And if the whole build-driver-privileges chain feels like a lot of yak shaving just to see which ports are open, that is the itch ScaniteX scratches — the scanning runs on our nodes, you just pick ranges and ports and collect the results. Happy scanning, and keep it legal.