How to identify and handle email forging and replay attacks?

Email marketer from Red Sift shares that to identify forged emails, check the email headers for inconsistencies, examine the sender's address for misspellings or unusual domains, and verify the authenticity of links before clicking on them. They also advise being wary of emails that request sensitive information or contain urgent requests.

Marketer from Email Geeks notes that DMARC is not passing, which is a good sign. Having an enforcement policy in place should provide reassurance that not all malicious emails will get through.

Email marketer from Reddit shares that spoofed emails can be reported to the email provider so that they can improve their spam filters.

Email marketer from StackExchange explains that SPF records can get you so far, but they can be complex and time consuming to maintain. He also suggests DKIM signatures. He recommends a few products that can help.

Email marketer from Quora shares that some replay attacks can be mitigated by only authenticating once using a session key. Another way is to add sequence numbers to requests and reject old requests. This prevents reuse of the same session key.

Email marketer from Valimail explains that implementing DMARC enforcement is crucial to preventing domain spoofing. By setting a DMARC policy of reject, organizations can instruct recipient mail servers to reject unauthenticated emails, effectively stopping spoofing attacks.

Email marketer from Proofpoint shares that organizations can use email authentication protocols (SPF, DKIM, DMARC) to detect and block spoofed emails. Monitoring email traffic for anomalies, such as sudden changes in sender IPs or email volume, can also help identify potential spoofing attacks.

Expert from Email Geeks identifies the issue as someone forging the user's email. The rDNS on the sending IPs looks like snowshoe spamming, possibly a replay attack. SPF is passing because niziloformation.monster is allowed to send from the IPs. The IPs are owned by the spammer and located in Russia. DKIM is weird, as a replay attack would typically show a passing DKIM.

Expert from Word to the Wise explains that one method to identify forged emails is to pay attention to domain reputation. Forged emails often come from domains with poor reputations. Using tools to monitor your own domain's reputation and identify any unauthorized sending sources can help mitigate damage.

Expert from Word to the Wise explains that responding to a replay attack will require multiple systems and different responses. DMARC and DKIM and SPF, the different types of authentication are all useful, but alone they may not stop the response.

Documentation from Microsoft Learn explains that spoofing is when an email message appears to be from someone other than the actual sender. They recommend using SPF, DKIM, and DMARC to prevent spoofing. SPF validates the sending mail server, DKIM adds a digital signature, and DMARC specifies how to handle emails that fail SPF or DKIM checks.

Documentation from NIST explains that replay attacks are the act of an attacker intercepting and fraudulently retransmitting a valid data transmission. Replay prevention measures should protect sensitive communications, prevent eavesdropping, and ensure privacy and authentication.

Documentation from DMARC.org explains that replay attacks involve an attacker intercepting and re-sending legitimate email messages. Implementing DMARC with a policy of reject or quarantine can significantly reduce the effectiveness of replay attacks, as it ensures that unauthorized messages are not delivered to recipients.

Documentation from Google Workspace Admin Help details that setting up SPF records can help prevent spoofing by specifying which mail servers are authorized to send email on behalf of your domain. They also advise using DMARC to instruct recipient mail servers on how to handle messages that fail authentication checks, either by quarantining or rejecting them.