This detection rule targets potential brand impersonation attacks specifically associated with the service DocSend. It aims to identify email threats where the attacker attempts to disguise themselves as a legitimate sender from DocSend. The logic checks several parameters: if the sender's display name closely resembles 'DocSend', if the domain contains 'docsend' (even if misspelled, using a Levenshtein distance of 1), and contradicts the legitimate domain verification where the domain should not be 'docsend.com'. Additionally, it excludes any sender emails that are part of the designated recipient emails list to minimize false positive alerts. The rule also reinforces security by negating trusted domains unless they fail DMARC authentication, ensuring that only genuine, failed DMARC messages flag for further review. This rule aids in identifying potential phishing attempts that might utilize social engineering tactics through brand impersonation and lookalike domains.