Clean install of Java 7 Update 9 yesterday, tried to join a meeting and got the Active X prompt to install add on, did that and then got the Admin prompt. Passwordless RDP Session Hijacking Feature All Windows versions. This post periodically updated, all updates in the end of the post. Blogpost in 2. 0 seconds Fun with sethc backdoored host somewhere in the internet Recently ive played with sethcutilman logon screen backdoors, and almost everytime i used just command line. Occasionally ive looked at Users tab in Task Manager taskmgr. When i checked it again with local admin rights, it failed by asking users password. Why and how that happenedLets dig deeper. Ive got it Sticky Keys cmd backdoor at windows login screen runs with NT AUTHORITYSYSTEM and have Full Control access permission, and can connect to EVERY user session without asking for a password. So weve got a session hijacking here. The most funny thing is that the legit user isnt asked for logout, by using this technique the user just will be kicked out of the session without any notification. Attack Vector Details. A privileged user, which can gain command execution with NT AUTHORITYSYSTEM rights can hijack any currently logged in users session, without any knowledge about his credentials. You probably think you know how to keep your internet habits secret. Clearing browser history is too obvious, you say. I just do all my sketchy stuff in an. Terminal Services session can be either in connected or disconnected state. This is high risk vulnerability which allows any local admin to hijack a session and get access to. Domain admin session. Any unsaved documents, that hijacked user works on. Any other systemsapplications in which hijacked user previously logged in May include another Remote Desktop sessions, Network Share mappings, applications which require another credentials, E mail etc. Example scenario. A stepbystep guide with screenshots to install Windows 8. USB flash drive. Unfortunately I cannot get this to work. I have the packages installed, and I have started the service without any errors. The service is not listening on ports 3389. TeamViewer Features Remote Control without Installation With TeamViewer you can remotely control any PC anywhere on the Internet. No installation is required, just. All windows privilege escalation session hijacking. Some bank employee have access to billing system, and its credentials to login. One day, he come to work, logging in to the billing system and start to work. At lunch time he will lock his workstation, and out to lunch. Then, system administrator gets to employees workstation, and logs in with his administrators account. According to the banks policy, administrators account should not have access to the billing system, but with couple of built in commands in windows, this system administrator will hijack employees desktop which he leaved locked. Install Teamviewer Without Admin Rights' title='Install Teamviewer Without Admin Rights' />From now, sysadmin can perform malicious actions in billing system as billing employee account. There are huge amount of scenarios like this. Furthermore, an attacker doesnt need to use tools like metasploit, incognito, mimikatz etc, which is commonly used for users token manipulation and impersonating logged in users. Everything is done with built in commands. Bill Of Material Format In Excel more. Every admin can impersonate any logged in user either locally with physical access or remotely via Remote Desktops see Po. C. Windows 2. 01. Ammyy-Admin_14.png' alt='Install Teamviewer Without Admin Rights' title='Install Teamviewer Without Admin Rights' />Confirmed by Kevin Beaumont Gossi. The. Dog. Windows 2. Gp0hAMot8/0.jpg' alt='Install Teamviewer Without Admin Rights' title='Install Teamviewer Without Admin Rights' />R2. We can talk about endless amount of examples. It can be done remotely, as shown in Proof of Concepts. An attacker can hijack active or disconnected session remotely via remote desktops. I use this technique about three weeks in my on going penetration tests on daily basis. It in very simple way helps me to get access to sensitive information like emails, opened documents, clear text passwords that administrators write down in notepad not intended for saving, but for temporally writing it somewhere, opened RDP sessions to another external domains think cloud, or another applications that make use of different login credentials. Someone can say, if you admin, you can dump servers memory and parse it. Thats correct, but you dont need it any more. Just two simple commands and you are in. The most incredible thing, is that I dont need to know the credentials of hijacked user, it is pure passwordless hijacking. A successful attack heavily related on time and gathered information. If you need to dump a memory, to get your sensitive info, youre in problem. That means that youve tried all quick wins that you know. In example of hijacking user active or disconnected while he is working now remotely on some sensitive server that i have no access to, and havent even knew about it, this technique allows me to compromise that server in less than a minute. Everything is real and from my own experience. Furthermore, as I understand it is very hard to catch if this attack happen. Kevin Beaumont Gossi. The. Dog make an alert on tscon. Microsoft OMS. I had a conversation about this finding with Benjamin Delpy gentilkiwi author of mimikatz That is normal Windows API, thats the design flow, they use it. As mentioned earlier, if you admin, you can do everything. But here is the point. Why and HOW you become admin If some unprivileged user becomes admin using some kind of local privilege escalation thats the problem and not the design flow we are talking about. You can do everything, even patch terminal services the way that it will accept your token and allow shadowing mode, without users knowledge., he said. Proof of Concept. Microsoft documentation helps us to do that from command line. All we need is NT AUTHORITYSYSTEM command line. Easiest method with psexec, but requires psexec. Another method is to create a service that will connect selected session to ours. Get all sessions information C Windowssystem. Hp Speakers Drivers there. USERNAME SESSIONNAME ID STATE IDLE TIME LOGON TIME. Disc 1 31. 22. PM. Active . 31. PM. C Windowssystem. Create service which will hijack users session C Windowssystem. SC Create. Service SUCCESS. Start service. Right after that your session will be replaced with target session.