Detection of Malicious Scripted Activity in Fileless Attacks

There is disclosed in one example a computing apparatus, including: a processor and memory; and instructions encoded within the memory to instruct the processor to: identify a scripted process for security analysis; hook application programming interface (API) calls of the scripted process to determine a plurality of pre-execution parameters and runtime parameters; assign individual scores to the pre-execution parameters and runtime parameters; compute a sum of the individual scores; compare the sum to a threshold; and detect malicious or suspicious activity if the sum is above the threshold.