Majority of the time the wipers will get the blame.
The actual linkage spindles were squeaking for me. Pop both wipers off, pop the rubber surround off and give the spingle a wiggle. Any movement? There's your issue.
Pack with grease for now and it'll be quite for a bit.
A permanent fix is to get a new linkage. A almost permanent solution is to actually bend the wiper arm so it's perpendicular to the screen. It's been covered a handful of times before and it worked for me!