The Soviet soldiers hated the SS. The cruelty of the SS was always present in Soviet Propaganda. Especially later on, everybody knew about the SS, knew about the war crimes perpetrated.

If normal soldiers got them in their hands, they treated them worse than Standard Wehrmacht Soldiers. The thing, many of the Soviets just wanted to capture SS because of their reputation and made every German soldiers out to be SS.

The thing with the shot on sight. The Soviet Army actually tried to take POW's and not murder every one of them on sight. If Protocol was followed, they were to be taken prisoners. If no one was there to enforce protocol and soldiers could get revenge I am sure that some SS or would-be SS were murdered. But I never read that this was an extremly widespread or common problem.

Source: Anthony Beevor; The Fall of Berlin 1945

In "Beyond the Rhine" by Donald Burgett, he mentions that they encountered a black uniformed SS towards the end of the war. He approached them unarmed and seemed quite arrogant. They (the US paratroopers) had liberated at least one of the death camps by this point. They beat the man unconscious and then rolled him off the bridge into the river.

This is just one case, but I'd guess it's probably representative of the difficulty an SS soldier faced in surviving initial capture.

Guy Sajer, in "The Forgotten Soldier" states that at the very end of the war, having made it back to Germany, his unit, Panzergrenadiers, tore the unit bands off the cuffs of their sleeves, because they didn't want to be mistaken for SS troops when they surrendered. So even though he'd just come from the Eastern front to the Western front, it sounds like there was an awareness that things didn't go well if you were surrendering SS.

I'm not sure how long after capture you're referring to, but whether or not the Allies had an official policy on the SS during the war, they certainly categorized them as guilty until proven innocent afterward simply by membership.

Here's a link to the actual judgement regarding the SS:

http://avalon.law.yale.edu/imt/judorg.asp#ss

I tried doing some digging for reputable academic references to the treatment of SS prisoners on capture, but unfortunately everything I was able to find quickly was basically tied to Nazi apologists using the stories to equate Allied treatment of the SS with German treatment of Jews and Russians.

Hopefully somebody with more knowledge on the topic can provide you some references, but everything I've read on the topic indicates that being a member of the Waffen SS let alone the Allgemeine SS was something prisoners tried to hide when possible. More so on the Eastern Front and by 1945 on the Western Front as well. The details may not all have been in public circulation but they were thought of as ideological Nazis rather than just soldiers doing their duty since most SS troops were volunteers.