New SessionShark Phishing Kit Bypasses MFA to Steal Office 365 Logins
Summary:
SessionShark is an advanced phishing kit that enables cybercriminals to bypass Microsoft Office 365 multi-factor authentication by stealing session tokens, granting unauthorized access even without the user’s one-time passcode. Discovered by security researchers at SlashNext, this adversary-in-the-middle toolkit impersonates legitimate Office 365 login pages to deceive users into submitting their credentials. When a victim attempts to log in via the spoofed portal, SessionShark intercepts and exfiltrates the username, password, and most critically, the session token effectively hijacking the user’s authenticated session.
What makes SessionShark especially dangerous is its real-time functionality. The kit integrates with a Telegram bot to provide attackers with immediate alerts once a victim submits their credentials, enabling them to act before session tokens expire. This instantaneous data exfiltration includes full session cookies, which are the authentication artifacts Office 365 uses to keep users logged in. With these, attackers can sidestep MFA entirely, gaining direct access to sensitive data, internal communications, and cloud resources.
Security Officer Comments:
SessionShark is not merely a standalone tool but part of a growing cybercrime-as-a-service trend. It is advertised on dark web and closed-access cybercrime forums under the pretense of “educational use,” a common tactic used to mask malicious intent and reduce legal liability for sellers. The phishing kit comes bundled with user-friendly interfaces, support, updates, and even guides, lowering the barrier for less technically sophisticated actors to launch impactful campaigns. This commoditization mirrors broader underground economies, where professional-grade hacking tools are increasingly sold like consumer software.
Technically, SessionShark also leverages Cloudflare’s reverse proxy services to conceal the true origin of its phishing sites, complicating takedown efforts and obscuring attacker infrastructure. Its phishing portals are designed to mimic Microsoft’s branding down to the smallest detail, increasing their success rate. Furthermore, the tool is built to evade traditional threat detection by avoiding known malicious domains and exploiting trusted infrastructure, making it challenging for security tools to identify or block.
Suggested Corrections:
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://hackread.com/sessionshark-phishing-kit-bypass-mfa-steal-office-365-logins/
SessionShark is an advanced phishing kit that enables cybercriminals to bypass Microsoft Office 365 multi-factor authentication by stealing session tokens, granting unauthorized access even without the user’s one-time passcode. Discovered by security researchers at SlashNext, this adversary-in-the-middle toolkit impersonates legitimate Office 365 login pages to deceive users into submitting their credentials. When a victim attempts to log in via the spoofed portal, SessionShark intercepts and exfiltrates the username, password, and most critically, the session token effectively hijacking the user’s authenticated session.
What makes SessionShark especially dangerous is its real-time functionality. The kit integrates with a Telegram bot to provide attackers with immediate alerts once a victim submits their credentials, enabling them to act before session tokens expire. This instantaneous data exfiltration includes full session cookies, which are the authentication artifacts Office 365 uses to keep users logged in. With these, attackers can sidestep MFA entirely, gaining direct access to sensitive data, internal communications, and cloud resources.
Security Officer Comments:
SessionShark is not merely a standalone tool but part of a growing cybercrime-as-a-service trend. It is advertised on dark web and closed-access cybercrime forums under the pretense of “educational use,” a common tactic used to mask malicious intent and reduce legal liability for sellers. The phishing kit comes bundled with user-friendly interfaces, support, updates, and even guides, lowering the barrier for less technically sophisticated actors to launch impactful campaigns. This commoditization mirrors broader underground economies, where professional-grade hacking tools are increasingly sold like consumer software.
Technically, SessionShark also leverages Cloudflare’s reverse proxy services to conceal the true origin of its phishing sites, complicating takedown efforts and obscuring attacker infrastructure. Its phishing portals are designed to mimic Microsoft’s branding down to the smallest detail, increasing their success rate. Furthermore, the tool is built to evade traditional threat detection by avoiding known malicious domains and exploiting trusted infrastructure, making it challenging for security tools to identify or block.
Suggested Corrections:
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://hackread.com/sessionshark-phishing-kit-bypass-mfa-steal-office-365-logins/