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DocuSign

2 mentions in 7 days · 2 in 30 days · 2 total · first seen · last

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Hackers Use Blob URLs and Microsoft Teams to Create Phishing Pages Inside Victims’ Browsers

Barracuda details a phishing campaign using Microsoft Teams OAuth redirects and browser blob URLs to render local fake DocuSign login pages for credential theft.

Barracuda researchers identified an active phishing campaign that routes DocuSign-themed emails with calendar invites through a Microsoft OAuth endpoint and crafted redirects into Microsoft Teams, then renders a fake sign-in page via a browser-generated blob URL. Because the page is assembled locally in memory and can register service workers and run in a sandboxed iframe, URL-reputation checks largely see legitimate Microsoft domains. The goal is credential theft and account takeover, not a flaw in Teams itself.

Cyber Security Newsupdated · 4d agofirst · 5d agoPhishing & fraud in the wild 13 sources

New Phishing Attack Uses Blob URLs to Hide Malicious Pages From Security Scanners

Barracuda detailed a DocuSign-themed phishing campaign that renders credential-harvesting pages as browser blob URLs, evading URL reputation and blocklist defenses.

Barracuda researchers report a credential-harvesting phishing campaign that starts with a DocuSign-themed email containing a calendar invitation and routes victims through legitimate Microsoft OAuth endpoints and Microsoft Teams. A crafted redirect parameter leads Teams to load external content from cdn.bloom[.]io, which the browser renders as a blob URL — a session-only address held in local memory with no persistent public URL to crawl, categorize, or blocklist. The locally generated page registers a service worker, runs inside a sandboxed iframe, and is dynamically steered by backend infrastructure, indicating a centrally managed phishing platform. Barracuda recommends phishing-resistant MFA such as FIDO2 keys and passkeys, monitoring OAuth flows and redirect chains, and Teams malicious URL protection.

GBHackersupdated · 4d agofirst · 5d agoPhishing & fraud in the wild 13 sources

Appears with

organization Barracuda 2product Microsoft Teams 2vendor Barracuda 2vendor DocuSign 2vendor Microsoft 2organization DocuSign 1organization Microsoft 1product Microsoft 365 1product Microsoft OAuth 1
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