Every detection engine has the same weakness: it can only catch what it knows about at the moment of scanning. A file that is clean by today's signatures but malicious by tomorrow's gets a free pass. Retrospective scanning attacks that gap directly — it goes back and re-checks delivered content against updated intelligence.
Votiro Cybersec Ltd.'s US10664602B2, “Determining malware prevention based on retrospective content scan” (issued May 26, 2020; CPC G06F 21/56 family — malware detection, and H04L 63/145 — malicious-traffic protection), describes basing the prevention decision on a scan performed after the fact, not only at the gateway. Read it at US10664602B2.
Mechanically, this means the system keeps enough context about delivered files to re-evaluate them when the threat picture changes — and to act (quarantine, alert, remediate) on a verdict that flips from clean to malicious. It is the security equivalent of a recall notice: the product was shipped, then later found defective, and the system can reach back to it.
Why this is a business story: content disarm and reconstruction, plus retrospective scanning, became the basis for a category of email and file-security vendors selling “zero-trust to the file” as a recurring service. The commercial logic is the same as MDR: the value is in the continuous re-evaluation, which only works as a subscription, not a one-time scan.
The grounded read: retrospective scanning accepts that day-zero detection will miss things and builds the ability to catch them after delivery. Votiro's 2020 grant frames malware prevention as a decision that can be made retrospectively, not only at the moment of entry.