Ensuring the integrity of logs is essential to reliably detect and counteract attacks, because adversaries tamper with logs to hide their activities on a computer. Even though some research studies proposed different ways to protect log files, adversaries can tamper with logs in kernel space with kernel-level malicious software (malware). In an environment where Virtual Machines (VM) are utilized, VM Introspection (VMI) is capable of collecting logs from VMs. However, VMI is not optimized for log protection and unnecessary overhead is incurred, because VMI does not specialize in log collection. To transfer logs out of a VM securely, we propose a secure log transfer method of replacing a library. In our proposed method, a process on a VM requests a log transfer by using the modified library, which contains a trigger for a log transfer. When a VM Monitor (VMM) detects the trigger, it collects logs from the VM and sends them to another VM. The proposed method provides VM-level log isolation and security for the mechanism itself. This paper describes design, implementation, and evaluation of the proposed method.