The disclosure herein describes the processing of malware scan requests from VCIs by an anti-malware scanner (AMS) on a host device. A malware scan request is received by the AMS from a VCI, the malware scan request including script data of a script from a memory buffer of the VCI. The AMS scans the script data of the malware scan request, outside of the VCI, and determines that the script includes malware. The AMS notifies the VCI that the script includes malware, whereby the VCI is configured to prevent execution of the script or take other mitigating action. The AMS provides scanning for fileless malware to VCIs on a host device without consuming or otherwise affecting resources of the VCIs.