Had an email with a PDF attachment that ESA AMP gave a disposition of LowRisk, then later changed the attachment to Malicious. This is good but why didn't ESA AMP catch it the first time? I ask this because Talos File Reputation list the Date Detection Created as 05/01/2018. The e-mail was delivered to us on 3/11/2019.
So why did ESA AMP give the PDF a LowRisk when Talos File Reputation knew about the Malicious Hash for 10 months?
SHA256
87136b978a3bd48adc9e8dfa4875407c80a462681961e202f1deabe5b5ff65cd