humiliating iis servers for fun and jail time
~/
humiliating iis servers for fun and jail time
13 min read
humiliating iis servers for fun and jail time
March 18, 2026 · 13 minutes read
A friend of mine once told me:
If you ever spot an IIS blue screen, don’t stop there; there must be something.
Yep, he was right. That IIS splash page is not a dead end. Behind that blue window sits one of the most consistently misconfigured web servers on the www, and it’s begging you to look deeper.
So let me walk you through how I approach IIS targets during bug bounty:
table of contents
psst, psst, IIS servers, where are you?
shodan
google dorking
active tech fingerprinting
ok, I found an IIS server. now what?
internal IP disclosure
pwn time
nuclei templates: automate the boring stuff
the HTTPAPI 2.0 dead end that isn’t
IIS tilde enumeration: the gift that keeps giving
using LLMs
github dorks to resolve shortnames
using BigQuery to resolve shortnames
bruteforcing the rest with crunch
fuzzing: the IIS-specific wordlist matters
web.config: the keys to the kingdom
path traversal to web.config
bin directory DLL exposure via cookieless sessions
reverse proxy path confusion
authentication bypass via NTFS hacks
file upload tricks
bypassing WAFs via HPP
psst, psst, IIS servers, where are you?
Here are some techniques I use to find IIS servers.
shodan
Before you even touch a target, go see what Shodan already knows:
ssl:"target.com" http.title:"IIS"<br>ssl.cert.subject.CN:"target.com" http.title:"IIS"<br>org:"target" http.title:"IIS"
These sample queries will list IIS boxes tied to the target’s org or SSL certificates. You’ll sometimes find staging servers, forgotten admin panels, and internal tools that nobody realized were internet-facing.
Feel free to replace or combine shodan with other platforms like fofa, censys, netlas, odin, etc. They all index different slices of the internet. 🍕
google dorking
Google can find IIS servers for you before you even fire up a scanner. These dorks are all about locating IIS targets within a scope:
site:target.com intitle:"IIS Windows Server"<br>site:target.com inurl:aspnet_client<br>site:target.com ext:aspx | ext:ashx | ext:asmx<br>site:target.com intext:"Microsoft-IIS" | intext:"X-Powered-By: ASP.NET"<br>site:target.com inurl:_vti_bin<br>site:target.com intitle:"Microsoft Internet Information Services"
The aspnet_client folder and _vti_bin (FrontPage extensions) are dead giveaways for IIS; if Google has indexed them, you’ve got a target. The ext:aspx dork catches any indexed ASP.NET pages, which means IIS is underneath.
Also, expand your scope with stacked wildcards to catch nested subdomains that basic enumeration misses:
site:*.target.com intitle:"IIS"<br>site:*.*.target.com intitle:"IIS"
That second one has surfaced dev/staging boxes for me more than once.
active tech fingerprinting
The easiest way to know you’re staring at IIS is the response headers. Hit it with a raw request:
nc -v target.com 80
Or if it’s TLS:
openssl s_client -connect target.com:443
What you’re looking for something like this in the response headers:
Server: Microsoft-IIS/10.0<br>X-Powered-By: ASP.NET
But probably you want to do this at scale . Then just keep calm and use httpx (or nuclei):
httpx -l targets.txt -td | grep IIS | tee iis-targets.txt
ok, I found an IIS server. now what?
First off, let’s confirm what we’re dealing with and grab as much information as the server is willing to give away for free.
internal IP disclosure
Here’s a freebie most people miss. Send an HTTP/1.0 request to certain IIS setups (especially Exchange or OWA fronts) and the server will sometimes hand you an internal IP in the Location header:
curl -v --http1.0 http://example.com
You might get back something like:
HTTP/1.1 302 Moved Temporarily<br>Location: https://192.168.5.237/owa/<br>Server: Microsoft-IIS/10.0<br>X-FEServer: NHEXCHANGE2016
That internal IP and that X-FEServer header just told you the internal hostname of the Exchange server. File that away. It’s information disclosure that we could leverage in the following steps.
pwn time
Enough recon by now, let’s get to the juicy parts.
nuclei templates: automate the boring stuff
Once you’ve got your list of IIS targets, blast them with nuclei using relevant tags:
nuclei -l iis-targets.txt \<br>-tags microsoft,windows,asp,aspx,iis,azure,config,exposure -silent
I like to fire this in the background while I’m doing manual recon.
the HTTPAPI 2.0 dead end that isn’t
You’ll hit a lot of IIS boxes that respond with a generic HTTPAPI 2.0 404 error. Most people see this and think “nothing here.” Wrong.
What this actually means is the server didn’t receive the right domain name in the Host header. The IIS instance is there, it’s running something, but it’s bound to a specific virtual host. You need to figure out which one.
Two approaches:
check the SSL certificate. The subject or SAN field often contains the hostname you need. Just hit it in a browser and...