Query: Outbound C2 pattern associated with Email Spoofing
Matching passage: T1684.002 Email Spoofing. Tactics: stealth. Description: Adversaries may fake, or spoof, a sender’s identity by modifying the value of relevant email headers in order to establish contact with victims under false pretenses.(Citation: Proofpoint TA427 April 2024) In addition to actual email content, email headers (such as the FROM header, which contains the email address of the sender) may also be modified. Email clients display these headers when emails appear in a victim's inbox, which may cause modified emails to appear as if they were from the spoofed entity. Enterprise environments can use Domain-based Message Authentication, Reporting, and Conformance (DMARC) as an email authentication protocol that references results of the Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) configurations. SPF and DKIM are configured separately in DNS: SPF verifies that the sending server is authorized for the domain, while DKIM uses a digital signature to verify email integrity and domain authentication. Together, they validate email authenticity and specify how receiving servers should handle authentication failures. Without enforced identity authentication, adversaries may compromise the integrity of an authentication check with altered headers that would not have otherwise passed.(Citation: Cloudflare DMARC, DKIM, and SPF)(Citation: DMARC-overview)(Citation: Proofpoint-DMARC) An example of a weak or absent DMARC policy is `v=DMARC1; p=none; fo=1;`. The `p=none`. The `p=none` indicates no action should be taken, and therefore no filtering action will take place, even if an email fails authentication checks (i.e., SPF and/or DKIM fail). When a DMARC policy indicates no action, the email will still be delivered to the victim’s inbox.(Citation: ic3-dprk) Adversaries have abused weak or absent DMARC policies to circumvent authentication checks and conceal social engineering attempts. Adversaries can alter email headers to include legitimate domain names with fake usernames or impersonate legitimate users via [Imperso
Near-miss passage: T1684.001 Impersonation. Tactics: stealth. Description: Adversaries may impersonate a trusted person or organization in order to persuade and trick a target into performing some action on their behalf. For example, adversaries may communicate with victims (via [Phishing for Information](https://attack.mitre.org/techniques/T1598), [Phishing](https://attack.mitre.org/techniques/T1566), or [Internal Spearphishing](https://attack.mitre.org/techniques/T1534)) while impersonating a known sender such as an executive, colleague, or third-party vendor. Established trust can then be leveraged to accomplish an adversary’s ultimate goals, possibly against multiple victims. In many cases of business email compromise or email fraud campaigns, adversaries use impersonation to defraud victims -- deceiving them into sending money or divulging information that ultimately enables [Financial Theft](https://attack.mitre.org/techniques/T1657). Adversaries will often also use social engineering techniques such as manipulative and persuasive language in email subject lines and body text such as `payment`, `request`, or `urgent` to push the victim to act quickly before malicious activity is detected. These campaigns are often specifically targeted against people who, due to job roles and/or accesses, can carry out the adversary’s goal. Impersonation is typically preceded by reconnaissance techniques such as [Gather Victim Identity Information](https://attack.mitre.org/techniques/T1589) and [Gather Victim Org Information](https://attack.mitre.org/techniques/T1591) as well as acquiring infrastructure such as email domains (i.e. [Domains](https://attack.mitre.org/techniques/T1583/001)) to substantiate their false identity.(Citation: Crowdstrike BEC) There is the potential for multiple victims in campaigns involving impersonation. For example, an adversary may Compromise Accounts targeting one organization which can then be used to support impersonation against other entities.(Citation: VEC)