A parsing error due to a signature-based malware definition file update is a totally plausible suspect! It would explain why the router is downloading “updates

A parsing error due to a signature-based malware definition file update is a totally plausible suspect! It would explain why the router is downloading “updates” but not firmware upgrades. Also, these signature files contain tons of hex strings and unusual characters used to identify the actual malware (IOCs). We rollback these updates all the time when a bad malware signature update pegs the AV scan daemon. They are released several times per month depending on the vendor. Someone more knowledgeable about ASUS asd can probably confirm/deny.