They use two remote access clients most likely because the second one gives them invisible filesystem access - you can't see what they're looking at. The first one is probably just simpler to connect and helps them get you over the hurdles of the second one (which there aren't many of)
I had one of these scammers call, who was insistent there was an XP machine with a virus. He called back three times in quick succession, the third time I repeated that I used linux, not XP, and "I know you're a scammer, you know you're a scammer, just fuck off". That seems to be what's required to make them stop.
A friend of mine had one of these calls and decided to play along - he followed all their instructions, but played the dumb user... neglecting to tell them he was in KDE on ubuntu, not XP. "Yes, I'm clicking on the button in the corner...". He had them on speakerphone while preparing dinner and whatnot, went through several staff including 'senior advisors', and it finally ended when the battery on his phone died an hour later...
Luckily I had warned my mother-in-law about these - she's safely on Ubuntu, but I keep everyone in the family aware of scams.
So she played along for at least 45 minutes, before telling them their mother would be ashamed of them and they should get a useful job like sweeping the streets!
This seems like the best approach, if you can spare the time - tie up so much of their time that it is uneconomic.
Speaking as an Australian that's had a few of these calls, it's kind of fun stringing them along the first few times and then after that you can just hand them off to the nearest grandmother or 13 year old and let them deal with it.
My nephew (13) thinks it's great fun to stretch these calls out as long as possible, but then he's into playing Skyrim & what not.
I had one of these scammers call, who was insistent there was an XP machine with a virus. He called back three times in quick succession, the third time I repeated that I used linux, not XP, and "I know you're a scammer, you know you're a scammer, just fuck off". That seems to be what's required to make them stop.
A friend of mine had one of these calls and decided to play along - he followed all their instructions, but played the dumb user... neglecting to tell them he was in KDE on ubuntu, not XP. "Yes, I'm clicking on the button in the corner...". He had them on speakerphone while preparing dinner and whatnot, went through several staff including 'senior advisors', and it finally ended when the battery on his phone died an hour later...