Help Notification/or Hacked Please help!?

[Confucius2nd]

Okay. So I'm sat in bed watching Tv, then a strange generic "Haha" came from my phone when it was on lock screen. I was completely taken aback and scared this has never happened at first I though it was a angry birds notification, but I then realised angry birds N.C doesn't sound like that, I think I've been tapped/hacked but my phone laughed voluntarily like a human laugh and I'm pretty freaked out. So I'd appreciate any conclusions or any similar stories to what it might be. Thanks.

 

[SiempreTuna]

Very strange!

I think I'd freak if my phone started laughing at me.

Has it done it again?

I'd say there is a small possibility that you've been hacked. The probability is you haven't, but if it was me, I would check my data (contacts, diary) is backed up and do a factory reset.

This is a bit of a pain as it removes all your settings, apps etc but for me, it's a case of better safe than sorry.

 

[Confucius2nd]

No It hasn't occurred again, but the strange thing is that a week prior to the laughing incident I did a factory reset due to lagging and too many apps, I do a anti- virus check everyday Norton and McAfee, so I'm completey baffled to why my phone did that...so I have done another factory reset which is a total pain. But I'm just wondering if I have like a undetectable virus that is difficult to root and get rid of?, I tried looking on Google for any similar incidents but no I just got stuff like "mysterious background noises while on the phone " but I wasn't even on my phone so I dunno whether to throw it out.