Recently I discussed how TorrentLocker spam was using email authentication for its spam runs. At the time, I suggested that these spam runs were using email authentication to gather information about victim networks and potentially improve the ability to evade spam filters. DomainKeys Identified Mail’s (DKIM) own specification mentions the possibility of messages with from “trusted sources” and with a…
Read MoreAnalysis by Marshall Chen, Yi Lee, and Joe Wu Brand owners frequently use SPF and DKIM to protect their brands from email forgery. For example, a brand owner could register the same domain name under multiple top-level domains (TLDs) (such as .com, .net, .org, etcetera) and announce SPF/DKIM records for all of these domains (even if they were not actively…
Read MoreEmail authentication and validation is one method that is used to help bring down the levels of spam and phishing by identifying senders so that malicious emails can be identified and discarded. Two frameworks are in common usage today; these are SPF and DKIM. SPF (Sender Policy Framework): Defined in RFC 7208, SPF provides a…
Read MoreDuring the last week of August 2014, we observed a salad spam surge caused by KELIHOS spambot. Salad spam contains gibberish words in the email body, and is usually employed by cybercriminals so as to bypass spam filters. Here are some samples we spotted: Figures 1-2: Screenshots of spammed messages Majority of this outbreak’s victims are from the…
Read More