I like 7-Zip http://p7zip.sourceforge.net/
(For this How-To I used 7-Zip for Windows from http://www.7-zip.org/ )
To get 7-Zip working in MobaXterm I downloaded the 7-Zip package from a cygwin mirror...
( I got p7zip-15.09-1.tar.xz from http://cygwin.localhost.equipment/x86/release/p7zip/ )
-rwxrwx--- 1 Administ UsersGrp 1043204 Feb 2 12:27 p7zip-15.09-1.tar.xz
Using 7-Zip for Windows I extracted the tar file from within the .tar.xz file
(right-click on p7zip-15.09-1.tar.xz -> 7-Zip -> Extract to "p7zip-15.09-1.tar\")
-rwxrwx--- 1 Administ UsersGrp 5283840 Feb 2 12:27 p7zip-15.09-1.tar
Then using 7-Zip for Windows again I extracted the contents of the tar file
(right-click on p7zip-15.09-1.tar -> 7-Zip -> Extract to "p7zip-15.09-1\")
drwxrwx--- 1 Administ UsersGrp 0 Feb 2 12:30 p7zip-15.09-1
Then in Windows Explorer I opened the directory it created ( p7zip-15.09-1 ) and right clicked on the usr directory and chose 7-Zip -> Add to "usr.zip" (NB: Choose usr.zip, not usr.7z here)
This created a .zip file containing the usr directory.
I then renamed usr.zip to p7zip.mxt3 and moved it to C:\Program Files (x86)\Mobatek\MobaXterm Personal Edition
I then restarted MobaXterm.