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Mallory pivots from this family to the IOCs, detections, and named campaigns that touch your stack, and pages you when something new lands.
1 CVE Mallory has correlated with this family across public research and vendor advisories. Each row links to the full Mallory page for that vulnerability.
On 22 July 2026, one day prior to Proofpoint’s recent joint release with the NSA on Russia-aligned threat actor TA488, the actor began a campaign abusing CVE-2026-42897, a cross-site scripting (XSS) vulnerability in Outlook Web Access (OWA). | This novel infection chain ends with a previously unknown JavaScript browser-based implant we call OWAReaper, purpose-built for persistent access inside OWA.
1 distinct threat actor attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
This novel infection chain ends with a previously unknown JavaScript browser-based implant we call OWAReaper, purpose-built for persistent access inside OWA.
18 distinct techniques documented for this family, organized by ATT&CK tactic.
A cmnd command for one-time execution of arbitrary code via eval().
TA488 began a campaign abusing CVE-2026-42897, a cross-site scripting (XSS) vulnerability in Outlook Web Access (OWA)... If the email is opened in Outlook Webmail, the Outlook Exchange server mishandles the HTML from the message and runs arbitrary JavaScript. | This allows a loader piece of JavaScript to use the onload= event handler to parse the rest of the message body, assemble a Base64 fragment, and execute it as encoded JavaScript.
It then calls UpdateFolder to grant itself Owner-level permissions to the "Default" user... This persistent access lives on the server-side and requires deliberate removal from the Exchange server; credential rotation and even full re-imaging of the targeted user’s device will not evict the actor.
It then calls UpdateFolder to grant itself Owner-level permissions to the "Default" user... This persistent access lives on the server-side and requires deliberate removal from the Exchange server; credential rotation and even full re-imaging of the targeted user’s device will not evict the actor.
It then checks for installed Outlook add-ins... with ReadWriteMailbox permissions; if it finds any, it uses those add-ins to call GetClientAccessToken to steal OAuth tokens.
msanalytics.json Raw OWA session blob from /owa/sessiondata.ashx. Contains session state, user identity, mailbox info, and configuration.
It then creates two invisible input elements in the DOM and waits for the browser's autofill to enter the username and password to gather the user’s OWA saved credentials.
It then calls UpdateFolder to grant itself Owner-level permissions to the "Default" user... This persistent access lives on the server-side and requires deliberate removal from the Exchange server; credential rotation and even full re-imaging of the targeted user’s device will not evict the actor.
The data to exfiltrate is first encrypted using AES-CTR, then Base32-encoded... For the HTTPS exfiltration method, OWAReaper attempts to send encrypted data masquerading as asset requests.
OWAReaper implements two distinct data exfiltration protocols. The primary method occurs over HTTPS... If the HTTPS method fails, OWAReaper will use DNS label tunneling...
For the HTTPS exfiltration method, OWAReaper attempts to send encrypted data masquerading as asset requests... If all image CDN proxies fail, OWAReaper HTTPS exfiltration falls back to direct communication with the C&C via an HTTP GET request.
3 indicators attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.
IPs, domains, and DNS infrastructure linked to this family.
File hashes (MD5, SHA-1, SHA-256) from samples and reports.
1 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.