Psexec runs on port 445 and 139 which means it runs with other Microsoft programs and can hide itself within the normal funcitons of the computer.
The problem with this? hackers look for tools like this to see how they can develop a next generation malware attacks.
In the coming months we will see new and novel methods. So as a security professional one must make sure that unless your systems need this process it is wiser not to have it on your servers especially (maybe a test platform is ok).
Microsoft is always making more and easier methods to use their software, but do not give enough thought of the security implications.
This sentence is interesting:
“Specify a valid user name in the Domain\User syntax if the remote process requires access to network resources or to run in a different account. Note that the password is transmitted in clear text to the remote system.”
so basically if you want to run some commands remotely then the password will be transmitted in clear text and easily captured.
My recommendation: do not use this useful tool until you test it for security it’s implications.