sethc.exe Possible Backdoor

critical Nessus Plugin ID 73026

Synopsis

A possible backdoor exists on the remote host.

Description

The copy of 'sethc.exe' in the Windows 'System32' directory on the remote host appears to have been modified, perhaps for use as a backdoor. Either or both of the 'InternalName' or 'OriginalFilename' file attributes no longer match the original file.

This file is part of the Windows 'Sticky Keys' functionality and is launched with SYSTEM privileges from a login screen when a Shift key is pressed several times. After replacing the original file with, for example, cmd.exe, an attacker with access to the host can bypass authentication and gain a command shell and, in turn, complete control of the host.

Solution

Verify the contents of the 'sethc.exe' file and, if appropriate, whether the system has been compromised.

See Also

https://attack.mitre.org/wiki/Technique/T1015/

http://www.nessus.org/u?d368e978

Plugin Details

Severity: Critical

ID: 73026

File Name: smb_sethc_backdoor.nasl

Version: 1.4

Type: local

Agent: windows

Family: Windows

Published: 3/14/2014

Updated: 11/15/2018

Supported Sensors: Nessus Agent, Nessus

Risk Information

CVSS v2

Risk Factor: Critical

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/o:microsoft:windows

Required KB Items: SMB/Registry/Enumerated