I just got a call on my cell phone from a number I don’t recognize. It has a +8 country code. Where on Earth did this call come from?
There doesn’t seem to be such a code. I’ve gone through a couple of tables and the closest I found was this:
+8
+81 Japan JP/JPN
+82 South Korea KR/KOR
+84 Vietnam VN/VNM
+850 North Korea KP/PRK
+852 Hong Kong HK/HKG
+853 Macau MO/MAC
+855 Cambodia KH/KHM
+856 Laos LA/LAO
+86 China CN/CHN
+870 Pitcairn Islands PN/PCN
+880 Bangladesh BD/BGD
+886 Taiwan TW/TWN
There’s also +800, which is an international toll-free prefix, and various other non-country-specific services within the +8 group.
Wikipedia has a long list of them.
The +8 indicates it’s from the Far East. As Floater posted, that includes a number of sub-codes for specific countries.
The digits 1-9 all indicate a region, within which specific country codes are assigned (except for 1, which goes straight to the country-subdivision level).
1 - United States, Canada, Caribbean
2 - Africa
3 - Europe
4 - Also Europe
5 - Mexico, Central America, South America
6 - Australia, South Pacific
7 - former Soviet Union
8 - Far East
9 - Middle East and South Asia
Great! Thanks, guys. Clearly not worth calling back 
I’ve had calls where the number is complete jibberish. It seems phone spammers can reset their call-display number to anything they want to disguise themselves.