There is provided a system and a computerized method of remediating one or more operations linked to a given program running in an operating system, the method comprising: querying a stateful model to retrieve a group of entities related to the given program; terminating at least a sub set of the group of entities related to the given program; generating a remediation plan including one or more operations linked to the given program, the one or more operations being retrieved based on the group in the stateful model; and executing the remediation plan by undoing at least part of the one or more operations linked to the given program thereby restoring state of the operating system to a state prior to the given program being executed. There is further provided a computerized method of detecting malicious code related to a program in an operating system in a live environment.