As it's a docx file we can extract all the individual parts using binwalk.
binwalk -e microsooft.docx
Then we navigate to /root/Desktop/_microsooft.docx.extracted/src/, open up oof.txt and Ctrl + F for flag.
flag{oof_is_right_why_gfxdata_though}
Alternatively, if you don't want to use the command line, change the extension to .zip and unzip
Navigate into the correct folder and open oof.txt. ctrl + F to search for the flag.
Volatile
The challenge hinted at the need to use the tool Volatility.
First we run volatility -f memdump.raw imageinfo on the dump to get the OS version. We then use the cmdscan command to check the most recently run commands.