I just got screwed out of 0.03 BTC because of a malware that changes any address you copy into the malware owner's address. It even used a vanity gen to make the two first characters of the address the same (I was sending to 1Gm..., so the malware created a 1Gm address).

1. Before sending, always check the first two and last two letters to make sure it is the same address you are copying!
2. If possible, check a random string in the middle and compare it! Even better.

Be vigilant, y'all!