RAT
CronRAT
A malware written in Bash that hides in the Linux calendar system on February 31st.
CronRAT is a Linux rat.
Background
A Bash-based malware that conceals itself within the Linux calendar system on the nonexistent date of February 31st. It has been observed in connection with Magecart attacks.
Source: Malpedia (Fraunhofer FKIE).