Due to escalating complexity of hardware design and manufacturing, integrated circuits (ICs) are designed and fabricated in multiple nations, so are software tools. It makes hardware security become more subject to various kinds of tampering in the supply chain. Hardware Trojan horses (HTHs) can be implanted to facilitate the leakage of confidential information or cause the failure of a system. Reliability Trojan is one of the main categories of HTH attacks because its behavior is progressive and thus hard to be detected, or not considered malicious. In this work, we propose to insert reliability Trojan into a circuit which can finely control the circuit lifetime as specified by attackers (or even designers), based on manipulating BTI-induced aging behavior in a statistical manner, with the consideration of process variations (PVs). Experimental results show that, given a specified lifetime target and under the influence of PVs, the circuit is highly likely to fail within a desired lifetime interval, at the cost of little area overhead.