I don't think this solves the world but as a quickfix for this particular exploit I ran:

sudo chattr -i $HOME/.shrc

sudo chattr -i $HOME/.profile

to make them immutable. I also added:

alias unlock-shrc="sudo chattr -i $HOME/.shrc"

alias lock-shrc="sudo chattr +i $HOME/.shrc"

To my profile to make it a bit easier to lock/unlock.