Sneaky2FA PhaaS Kit Now Uses Redteamers' Browser-In-The-Browser Attack
Summary:
Push researchers identified a new evolution in the Sneaky2FA Phishing-as-a-Service kit: the integration of Browser-in-the-Browser phishing capabilities. Sneaky2FA, already known for its MFA-bypass features and Telegram-based distribution, now deploys phishing pages that simulate legitimate pop-up authentication windows containing embedded reverse-proxy login forms. The observed campaign used the domain previewdoc[.]us, a Cloudflare Turnstile challenge to block bots, and a fake Microsoft “Sign in” prompt styled as an Adobe document viewer. The BITB window dynamically adjusts to the victim’s operating system and browser, helping mask malicious URLs and increase realism. Once credentials and session cookies are entered, Sneaky2FA steals both for immediate account takeover.
The kit continues to rely on extensive evasion methods: bot-detection, conditional loading that redirects unwanted visitors to benign pages, anti-analysis functions that block developer tools, heavy JavaScript/HTML obfuscation, and fast domain rotation using long randomized paths on compromised or benign-looking domains. This mirrors broader PhaaS trends, with other kits such as Raccoon0365 also adding BITB functionality. The update reflects rapid criminal innovation and highlights the growing sophistication of turnkey phishing kits capable of bypassing MFA and defeating traditional email and web defenses.
Security Officer Comments:
Sneaky2FA’s adoption of BITB marks another step in the professionalization of PhaaS ecosystems, where features once limited to advanced threat actors are now available to low-skill operators. By combining reverse-proxy capabilities with visually convincing BITB overlays, attackers can bypass phishing-resistant flows and harvest usable session cookies with minimal friction. The layered evasion strategy, bot challenges, conditional routing, anti-analysis logic, and domain churn, demonstrates that these kits are deliberately engineered to avoid automated scanning and maximize operational lifespan. The addition of BITB to multiple PhaaS offerings suggests broader adoption is imminent, increasing the likelihood of successful identity compromise even for organizations with strong authentication controls.
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://www.bleepingcomputer.com/ne...ses-redteamers-browser-in-the-browser-attack/
https://pushsecurity.com/blog/analyzing-the-latest-sneaky2fa-phishing-page/#id-how-push-can-help
Push researchers identified a new evolution in the Sneaky2FA Phishing-as-a-Service kit: the integration of Browser-in-the-Browser phishing capabilities. Sneaky2FA, already known for its MFA-bypass features and Telegram-based distribution, now deploys phishing pages that simulate legitimate pop-up authentication windows containing embedded reverse-proxy login forms. The observed campaign used the domain previewdoc[.]us, a Cloudflare Turnstile challenge to block bots, and a fake Microsoft “Sign in” prompt styled as an Adobe document viewer. The BITB window dynamically adjusts to the victim’s operating system and browser, helping mask malicious URLs and increase realism. Once credentials and session cookies are entered, Sneaky2FA steals both for immediate account takeover.
The kit continues to rely on extensive evasion methods: bot-detection, conditional loading that redirects unwanted visitors to benign pages, anti-analysis functions that block developer tools, heavy JavaScript/HTML obfuscation, and fast domain rotation using long randomized paths on compromised or benign-looking domains. This mirrors broader PhaaS trends, with other kits such as Raccoon0365 also adding BITB functionality. The update reflects rapid criminal innovation and highlights the growing sophistication of turnkey phishing kits capable of bypassing MFA and defeating traditional email and web defenses.
Security Officer Comments:
Sneaky2FA’s adoption of BITB marks another step in the professionalization of PhaaS ecosystems, where features once limited to advanced threat actors are now available to low-skill operators. By combining reverse-proxy capabilities with visually convincing BITB overlays, attackers can bypass phishing-resistant flows and harvest usable session cookies with minimal friction. The layered evasion strategy, bot challenges, conditional routing, anti-analysis logic, and domain churn, demonstrates that these kits are deliberately engineered to avoid automated scanning and maximize operational lifespan. The addition of BITB to multiple PhaaS offerings suggests broader adoption is imminent, increasing the likelihood of successful identity compromise even for organizations with strong authentication controls.
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://www.bleepingcomputer.com/ne...ses-redteamers-browser-in-the-browser-attack/
https://pushsecurity.com/blog/analyzing-the-latest-sneaky2fa-phishing-page/#id-how-push-can-help