secure use of psexec?

As of March 7, 2014 PsExec now "encrypts all communication between local and remote systems, including the transmission of command information such as the user name and password under which the remote program executes."

with that said i still have problem with security i must solve . if i will use it to remote execute a script on my entire network it will be done using highly priviliged account. those credintals will remain in memory of each of the workstations i will run the script against(if one of those workstations is infected with malware it can be problematic)... any way to avoid that ? if i will run it using the system parameter will it still hold my domain account credintals? is there any way that my credintals wont be in the memory using psexec ?