Microsoft Copilot Spoofing: A New Phishing Vector
Summary:
This report details a sophisticated phishing campaign targeting users of Microsoft Copilot, a relatively new Generative AI service. Attackers are leveraging the novelty of Copilot and the widespread usage of the Microsoft ecosystem in organizations to deceive employees. The attack begins with a spoofed invoice email, designed to appear as if it originates from "Co-pilot," prompting users to click a link for payment. A telling indicator of malicious activity is the sender address in this spoofed email, which is not an official Microsoft email address. This link leads to a spoofed landing page that directs the victim to a fake Microsoft Copilot sign-in page, hosted on a suspicious non-Microsoft domain, which steals user credentials. The final stage involves a fake Microsoft Authenticator MFA page, providing the attackers with a window to act on the stolen credentials before the user realizes the compromise. The campaign exploits user unfamiliarity with Copilot's billing and communication practices, as well as the trust placed in Microsoft branding, highlighting the new attack surface introduced by new technologies.
Security Officer Comments:
This attack underscores the persistent challenge of adapting security measures to the rapid evolution of AI technology and its cybercriminal abusers. The attacker’s successful exploitation of user unfamiliarity with Microsoft Copilot highlights a critical gap in an organization’s security awareness training. While organizations focus on traditional phishing vectors, the introduction of Generative AI tools like Copilot necessitates a prioritization of educating users about the specific communication and billing practices associated with these new services. The attackers' meticulous replication of Microsoft's branding and login interfaces demonstrates the increasing sophistication of phishing lures.
The use of a fake MFA page is interesting, as it seems the adversary has no intention of stealing MFA codes. This fake MFA page appears to be intended to help buy the adversary time to utilize the compromised credentials and potentially vertically escalate privileges and pivot to other systems. Furthermore, the reliance on a non-Microsoft domain for the phishing page, while a red flag for vigilant users, emphasizes the need for security tools that can automatically visually flag suspicious URLs. Moving forward, organizations must prioritize proactive communication strategies, including visual aids and regular updates on new service protocols, to empower employees to identify and report these increasingly complex threats. In addition, organizations should consider implementing more robust email filtering and URL analysis tools that can detect and block these types of attacks before they reach the user's inbox.
Suggested Corrections:
IOCs are available here.
Users should always be cautious of individuals or organizations that ask for personal information. Most companies will not ask for sensitive data from their customers. If in doubt, users should verify with the company itself to avoid any potential issues.
Users should always take a close look at the sender’s display name when checking the legitimacy of an email. Most companies use a single domain for their URLs and emails, so a message that originates from a different domain is a red flag.
As a general rule, users should not click links or download files even if they come from seemingly “trustworthy” sources.
Check for mismatched URLs. While an embedded URL might seem perfectly valid, hovering above it might show a different web address. In fact, users should avoid clicking links in emails unless they are certain that it is a legitimate link.
Users should always be on the lookout for any grammatical errors and spelling mistakes. Legitimate companies will often employ proofreaders and editors who ensure that the materials they send out are error-free.
Users should not be frightened or intimidated by messages that have an alarmist tone. They should double check with the company if they are uncertain about the status of their accounts.
Phishing emails are designed to be sent to a large number of people, so they need to be as impersonal as possible. Users should check whether the message contains a generic subject and greeting, as this can be a sign of a phishing attempt.
Although not every end user has access to advanced anti-phishing software, they can still use the built-in protection of their email clients to filter messages. One example is setting the email client to block all images unless approved.
Legitimate companies will never send confirmation emails unless there are specific reasons for doing so. In fact, most companies will avoid sending unsolicited messages unless it’s for company updates, newsletters, or advertising purposes.
Users should always take the context of an email or message into account. For example, most online accounts do away with viewable member numbers, so users should be wary if they receive emails containing a “member number” for services that generally don’t use them.
It is important to take note of unusual information in the text of the message. Any mentions of operating systems and software that are not typically used by consumers can often be indicators of a phishing attempt.
If it seems suspicious, it probably is. Users should always err on the side of caution when it comes to sending out personally identifiable information through messages and emails.
Link(s):
https://cofense.com/blog/microsoft-copilot-spoofing-a-new-phishing-vector
This report details a sophisticated phishing campaign targeting users of Microsoft Copilot, a relatively new Generative AI service. Attackers are leveraging the novelty of Copilot and the widespread usage of the Microsoft ecosystem in organizations to deceive employees. The attack begins with a spoofed invoice email, designed to appear as if it originates from "Co-pilot," prompting users to click a link for payment. A telling indicator of malicious activity is the sender address in this spoofed email, which is not an official Microsoft email address. This link leads to a spoofed landing page that directs the victim to a fake Microsoft Copilot sign-in page, hosted on a suspicious non-Microsoft domain, which steals user credentials. The final stage involves a fake Microsoft Authenticator MFA page, providing the attackers with a window to act on the stolen credentials before the user realizes the compromise. The campaign exploits user unfamiliarity with Copilot's billing and communication practices, as well as the trust placed in Microsoft branding, highlighting the new attack surface introduced by new technologies.
Security Officer Comments:
This attack underscores the persistent challenge of adapting security measures to the rapid evolution of AI technology and its cybercriminal abusers. The attacker’s successful exploitation of user unfamiliarity with Microsoft Copilot highlights a critical gap in an organization’s security awareness training. While organizations focus on traditional phishing vectors, the introduction of Generative AI tools like Copilot necessitates a prioritization of educating users about the specific communication and billing practices associated with these new services. The attackers' meticulous replication of Microsoft's branding and login interfaces demonstrates the increasing sophistication of phishing lures.
The use of a fake MFA page is interesting, as it seems the adversary has no intention of stealing MFA codes. This fake MFA page appears to be intended to help buy the adversary time to utilize the compromised credentials and potentially vertically escalate privileges and pivot to other systems. Furthermore, the reliance on a non-Microsoft domain for the phishing page, while a red flag for vigilant users, emphasizes the need for security tools that can automatically visually flag suspicious URLs. Moving forward, organizations must prioritize proactive communication strategies, including visual aids and regular updates on new service protocols, to empower employees to identify and report these increasingly complex threats. In addition, organizations should consider implementing more robust email filtering and URL analysis tools that can detect and block these types of attacks before they reach the user's inbox.
Suggested Corrections:
IOCs are available here.
Users should always be cautious of individuals or organizations that ask for personal information. Most companies will not ask for sensitive data from their customers. If in doubt, users should verify with the company itself to avoid any potential issues.
Users should always take a close look at the sender’s display name when checking the legitimacy of an email. Most companies use a single domain for their URLs and emails, so a message that originates from a different domain is a red flag.
As a general rule, users should not click links or download files even if they come from seemingly “trustworthy” sources.
Check for mismatched URLs. While an embedded URL might seem perfectly valid, hovering above it might show a different web address. In fact, users should avoid clicking links in emails unless they are certain that it is a legitimate link.
Users should always be on the lookout for any grammatical errors and spelling mistakes. Legitimate companies will often employ proofreaders and editors who ensure that the materials they send out are error-free.
Users should not be frightened or intimidated by messages that have an alarmist tone. They should double check with the company if they are uncertain about the status of their accounts.
Phishing emails are designed to be sent to a large number of people, so they need to be as impersonal as possible. Users should check whether the message contains a generic subject and greeting, as this can be a sign of a phishing attempt.
Although not every end user has access to advanced anti-phishing software, they can still use the built-in protection of their email clients to filter messages. One example is setting the email client to block all images unless approved.
Legitimate companies will never send confirmation emails unless there are specific reasons for doing so. In fact, most companies will avoid sending unsolicited messages unless it’s for company updates, newsletters, or advertising purposes.
Users should always take the context of an email or message into account. For example, most online accounts do away with viewable member numbers, so users should be wary if they receive emails containing a “member number” for services that generally don’t use them.
It is important to take note of unusual information in the text of the message. Any mentions of operating systems and software that are not typically used by consumers can often be indicators of a phishing attempt.
If it seems suspicious, it probably is. Users should always err on the side of caution when it comes to sending out personally identifiable information through messages and emails.
Link(s):
https://cofense.com/blog/microsoft-copilot-spoofing-a-new-phishing-vector