I have two Macs on Yosemite, and one got a malware/adware bug that will not go away. I am going to do a fresh install, and would like to use Time Machine to restore to the point before the malware was installed (I know the time it happened). Can I use my working mac to reset the bad macs time machine folder to the appropriate time? I have seen many other posts on using tmutil to do similar things, but not this exactly. Thanks!