We need to find the malware name for a Bitcoin address. Bitcoin address is the following.

1Mz7153HMuxXTuR2R1t78mGSdzaAtNbBWX

Just search for 1Mz7153HMuxXTuR2R1t78mGSdzaAtNbBWX malware and you will be able to find the flag. Here is a hint…

picoCTF{P…a}