Various services through smartphones or personal computers have become common nowadays. Accordingly, embedded malware is rapidly increasing. The malware is infiltrated by using short message service (SMS), wireless networks, and random calling and makes smartphones bots in botnets. Therefore, in a system without an appropriate deterrent, smartphones are infiltrated easily. In the security threats by malware, random calling has become serious nowadays. To develop the defensive system against random calling and prevent the infiltration of the malware through random calling, it is required to understand the exact process of how to make bots in the botnet. Thus, this research develops a simple and ingenious mobile botnet covert network based on adjustable ID units (SIMBAIDU) to investigate how a botnet network is established by using phone numbers. Perfect octave coding (P8 coding) turns out to be effective in infiltrating smartphones and executing commands, which is used for botnets. The results provide the basic process of P8 coding which is useful for developing defensive systems of smartphones.