can hackers do this?

While training this morning I went to a map in ToT (just call it map "A"). As usual there was a hacker just on it and all the drops were still laying around. I figure they're gone for now so I start grinding and notice that I'm getting x2 drop on all the new spawned mobs. I didn't see any notice about an event x2 drop and I was getting normal xp. I go back 2 maps to a lower level map to test it out and I find that I'm getting regular drop/xp. I go back to map "A" and I'm still getting x2 drop. I changed channels and x2 drop is still in effect there on map "A" on other channels, but no other maps.

Huh?