If you're looking for a challenging hike in Mexico, this may be your third toughest option (second…read moreto Orizaba in Veracruz and Popo, respectively). That said, the first two may not be your safest options. Crime is reportedly an issue at Orizaba and as far as Popo ... well, that's an active volcano.
Malinche has been dormant for several hundred years, as I understand. But at least as of this review, this mountain is protected by and patrolled by mountain police. The police advised my group of 7 that there are several injuries per day. The peak here is about 14,500 feet. The terrain consists of rather loose dirt, rock and sand, presenting major issues with grip. Of my group of 7, 4 of us made it to the peak. I was not one of them. Beer at a late night concert the night before, coupled with an early start was a recipe for disaster. I also got one of the worst sunburns I've ever had. If you think you've applied enough lotion, you probably haven't. Separately, helmets and poles are highly recommended. My group scoffed at this, but by the end, we wished we had heeded the guide's advice.
I highly recommend starting as early as possible. My group started at 7:30 AM, which wasn't early enough. We did not get back to base until about 4 PM, but that's only because the police were kind enough to drive us back to the start from about the midway point on the decline. Otherwise, I think we might not have returned until about 6:30 or so.