Nowadays, several tools have been proposed to support the operations performed during a security assessment process. In particular, it is a common practice to rely on automated tools to carry out some phases of this process in an automatic or semiautomatic way. In this article, we focus on tools for the automatic generation of custom executable payloads. Then, we will show how these tools can be transformed, through some human-oriented modifications on the generated payloads, into threats for a given asset's security. The danger of such threats lies in the fact that they may not be detected by common antivirus (AVs). More precisely, in this article, we show a general approach to make a payload generated through automated tools run undetected by most AVs. In detail, we first analyze and explain most of the methods used by AVs to recognize malicious payloads and, for each one of them, we outline the relative strengths and flaws, showing how these flaws could be exploited using a general approach to evade AVs controls, by performing simple human-oriented operations on the payloads. The testing activity we performed shows that our proposal is helpful in evading virtually all the most popular AVs on the market. Therefore, low-skilled malicious users could easily use our approach.