A primary goal of our Industry Cyber Exposure Reports (ICERs) is to provide insight into how well cybersecurity controls are being implemented across the globe, with the hope that this external, composite view will effect noticeable, positive change that will make us all safer when we venture online.
It’s been just over a year since we released our inaugural ICER on the Fortune 500, so we decided to take a quick look at a key control, DMARC (email safety), one year later to see whether there has been any improvement. Spoiler alert: There has been!
Before we dig into the results, we need to note that we’ve modified the way we check for DMARC since the 2018 Fortune 500 report. Previously, we did a DMARC presence and syntax validity check for each set of mail domains and/or apex domains (depending on how the organizations configured their DNS records). Unfortunately, DMARC doesn’t exist in the vacuum of a single DNS TXT record and requires accurate configurations of a combination of DNS records types to make the system work. Starting with the FTSE 250 ICER, Rapid7 Labs began doing a full check of MX, SPF, DKIM, and DMARC for each organization. These enhanced checks helped identify a serious, common configuration issue in the Nikkei 225 ICER and—after using the new methodology on the Fortune 500 domain corpus—also identified different types of issues on a handful of these domains
2017 Fortune 500 List Total Year-Over-Year DMARC Change
As seen in the figure above, 92 organizations added a valid DMARC configuration of at least “none” to their primary email domain, ..