Update ponystealer.txt
Update ponystealer.txt

[0] https://blog.talosintelligence.com/2018/10/threat-roundup-1012-1019.html
[1] https://www.virustotal.com/#/file/22ef53123754caa2ac3871eb01221c99482e4318b59a30c8f07b9525afae52bd/detection

sub-string ```p0ny``` as an indicator.
stamparm/maltrail,stamparm/maltrail,stamparm/maltrail,stamparm/maltrail