faxhell - A Bind Shell Using the Fax Service and a DLL Hijack

(180 views)

A Proof-of-Concept bind shell using the Fax service and a DLL hijack based on Ualapi.dll. See our writeup at: https://windows-internals.com/faxing-your-way-to-system/ How to use Build Ualapi.dll and place in c:\windows\system32 Start the Fax service, which will load the DLL and call the export UalStart. UalStart will queue a thread pool work item that will open a handle to RpcSs, find a SYSTEM token, and then impersonate it. Afterward, it will create a socket on the local endpoint address, bind it to port 9299, and then asynchronously wait for a connection using a thread pool I/O completion port. Connect to the socket on port 9299 using your favorite client (such nc(at).exe <ip> 9299) and then type let me in and press ENTER. If you're writing custom code, make sure to send the string let me in\n. The I/O completion packet will then wake up the thread pool callback, which will start a....

July 7, 2020
Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments
© HAKIN9 MEDIA SP. Z O.O. SP. K. 2023
What certifications or qualifications do you hold?
Max. file size: 150 MB.
What level of experience should the ideal candidate have?
What certifications or qualifications are preferred?

Download Free eBook

Step 1 of 4

Name(Required)

We’re committed to your privacy. Hakin9 uses the information you provide to us to contact you about our relevant content, products, and services. You may unsubscribe from these communications at any time. For more information, check out our Privacy Policy.