Malware on your Android device picked up from third party app stores (FDroid? Amazon?) that steals email accounts and auth tokens. Looks like it only works on the older Android 4 Jellybean software (and some Android 5 Lollipop) and below, so mostly concentrated in Asia where there are lower-end phones.
You can see if your account has been affected here:
You can see if your account has been affected here:
https://gooligan.checkpoint.com/