{"id":13141,"date":"2026-05-26T04:04:00","date_gmt":"2026-05-26T04:04:00","guid":{"rendered":"https:\/\/serisec.com\/index.php\/2026\/05\/26\/33018\/"},"modified":"2026-05-26T04:04:00","modified_gmt":"2026-05-26T04:04:00","slug":"33018","status":"publish","type":"post","link":"https:\/\/serisec.com\/index.php\/2026\/05\/26\/33018\/","title":{"rendered":"Possible ACR Stealer From Page Impersonating Claude, (Tue, May 26th)"},"content":{"rendered":"<p>    Possible ACR Stealer From Page Impersonating Claude, (Tue, May 26th)<br \/>\n \t<BR><br \/>\n<BR><\/BR><br \/>\n    <!-- no image --><br \/>\n \t<BR><br \/>\n<BR><\/BR><\/p>\n<div>\n<p><em><strong>Introduction<\/strong><\/em><\/p>\n<p>In recent weeks, I&#8217;ve searched for pages impersonating Claude that distribute malware. In recent weeks, I&#8217;ve reliably found these sites through malicious ads in Google searches that lead to these pages, often concealed in URLs for <span style=\"font-family:Courier New,Courier,monospace;\">sites.google[.]com<\/span>, such as <a href=\"https:\/\/malware-traffic-analysis.net\/2026\/05\/11\/index.html\">this example from 2026-05-11<\/a>.<\/p>\n<p>These fake Claude pages generally show instructions for macOS malware when viewed through a macOS system, and they will show instructions for Windows malware when viewed through a Windows system. Today&#8217;s dairy shows an example of Windows malware from one of these pages seen on Monday, 2026-05-25. Based on the C2 domain for post-infection traffic, this appears to be an infection for\u00a0<a href=\"https:\/\/malpedia.caad.fkie.fraunhofer.de\/details\/win.acr_stealer\">ACR Stealer<\/a>.<\/p>\n<p><em><strong>Images<\/strong><\/em><\/p>\n<p><a href=\"https:\/\/i0.wp.com\/isc.sans.edu\/diaryimages\/images\/2026-05-25-ISC-diary-image-01a.png?ssl=1\"><img data-recalc-dims=\"1\" decoding=\"async\" alt=\"\" src=\"https:\/\/i0.wp.com\/isc.sans.edu\/diaryimages\/images\/2026-05-25-ISC-diary-image-01.png?ssl=1\" style=\"border-width: 2px; border-style: solid;\"><\/a><br \/>\n<em>Shown above: Web page impersonating Claude with a button to &#8220;Download for Windows.&#8221;<\/em><\/p>\n<p><a href=\"https:\/\/i0.wp.com\/isc.sans.edu\/diaryimages\/images\/2026-05-25-ISC-diary-image-02a.png?ssl=1\"><img data-recalc-dims=\"1\" decoding=\"async\" alt=\"\" src=\"https:\/\/i0.wp.com\/isc.sans.edu\/diaryimages\/images\/2026-05-25-ISC-diary-image-02.png?ssl=1\" style=\"border-width: 2px; border-style: solid;\"><\/a><br \/>\n<em>Shown above: Instructions to install Claude on Windows are actually instructions that will infect a vulnerable computer with malware.<\/em><\/p>\n<p><a href=\"https:\/\/i0.wp.com\/isc.sans.edu\/diaryimages\/images\/2026-05-25-ISC-diary-image-03a.png?ssl=1\"><img data-recalc-dims=\"1\" decoding=\"async\" alt=\"\" src=\"https:\/\/i0.wp.com\/isc.sans.edu\/diaryimages\/images\/2026-05-25-ISC-diary-image-03.png?ssl=1\" style=\"border-width: 2px; border-style: solid;\"><\/a><br \/>\n<em>Shown above: Traffic from a Windows host when following instructions from the fake Claude download page.<\/em><\/p>\n<p><em><strong>Indicators of Compromise<\/strong><\/em><\/p>\n<p>Fake Claude download page:<\/p>\n<ul style=\"margin-left: 40px;\">\n<li><span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/fairpoint29.com\/<\/span><\/li>\n<\/ul>\n<p>From the above page, URL for the initial download:<\/p>\n<ul style=\"margin-left: 40px;\">\n<li><span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/primemetricsa[.]com\/1518925<\/span><\/li>\n<\/ul>\n<p>Follow-up download:<\/p>\n<ul style=\"margin-left: 40px;\">\n<li><span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/6ryuefl.creativecommunityinfo[.]art\/Camel-91267b64-989f-49b4-89b4-9e015844d42d<\/span><\/li>\n<\/ul>\n<p>A further download:<\/p>\n<ul style=\"margin-left: 40px;\">\n<li><span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/i.ibb[.]co\/Xx16sbMz\/init-block.jpg<\/span><\/li>\n<\/ul>\n<p>Domain for post-infection HTTPS traffic to C2 server:<\/p>\n<ul style=\"margin-left: 40px;\">\n<li><span style=\"font-family:Courier New,Courier,monospace;\">yw.enhanceblabber[.]cc<\/span><\/li>\n<\/ul>\n<p>Initial download:<\/p>\n<p>SHA256 hash:\u00a0<a href=\"https:\/\/www.virustotal.com\/gui\/file\/70b5ecc110e074dbca92932c0e840ea3492ea0a43c3f215b71392c12b02213b2\"><span style=\"font-family:Courier New,Courier,monospace;\">70b5ecc110e074dbca92932c0e840ea3492ea0a43c3f215b71392c12b02213b2<\/span><\/a><\/p>\n<ul style=\"margin-left: 40px;\">\n<li>File size:\u00a02,416,902 bytes<\/li>\n<li>File type:\u00a0Zip archive data, at least v1.0 to extract<\/li>\n<li>File location:\u00a0<span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/primemetricsa[.]com\/1518925<\/span>\n<\/li>\n<li><span style=\"font-family:Arial,Helvetica,sans-serif;\">NOTE: There&#8217;s an issue with this zip archive, so its contents will not extract correctly using typical extraction tools.<\/span><\/li>\n<\/ul>\n<p>Follow-up download, PowerShell script:<\/p>\n<p>SHA256 hash:\u00a0<a href=\"https:\/\/www.virustotal.com\/gui\/file\/a14c3ecf5eb3d2543358482e43dc765dbf9ee7a4bec7571f5ecb8829ca719692\/content\"><span style=\"font-family:Courier New,Courier,monospace;\">a14c3ecf5eb3d2543358482e43dc765dbf9ee7a4bec7571f5ecb8829ca719692<\/span><\/a><\/p>\n<ul style=\"margin-left: 40px;\">\n<li>File size:\u00a04,177,395 bytes<\/li>\n<li>File type:\u00a0ASCII text, with very long lines, with CRLF line terminators<\/li>\n<li>File location:\u00a0<span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/6ryuefl.creativecommunityinfo[.]art\/Camel-91267b64-989f-49b4-89b4-9e015844d42d<\/span>\n<\/li>\n<\/ul>\n<p>A further download:<\/p>\n<p>SHA256 hash:\u00a0<a href=\"https:\/\/www.virustotal.com\/gui\/file\/47fa746422f1bf6b7712dc6803378e6a995488007193a7441d790f70d204728f\"><span style=\"font-family:Courier New,Courier,monospace;\">47fa746422f1bf6b7712dc6803378e6a995488007193a7441d790f70d204728f<\/span><\/a><\/p>\n<ul style=\"margin-left: 40px;\">\n<li>File size:\u00a0628,035 bytes<\/li>\n<li>File type:\u00a0JPEG image data, JFIF standard 1.01, aspect ratio, density 1&#215;1, segment length 16, baseline, precision 8, 5256&#215;5256, components 3<\/li>\n<li>File location:\u00a0<span style=\"font-family:Courier New,Courier,monospace;\">hxxps[:]\/\/i.ibb[.]co\/Xx16sbMz\/init-block.jpg<\/span>\n<\/li>\n<li><span style=\"font-family:Arial,Helvetica,sans-serif;\">NOTE: This image doesn&#8217;t appear to be malicious, nor could I find any obvious signs of embedded data, but it&#8217;s somehow related to this infection chain.<\/span><\/li>\n<\/ul>\n<p>&#8212;<br \/>\nBradley Duncan<br \/>\nbrad [at] malware-traffic-analysis.net<\/p>\n<p> (c) SANS Internet Storm Center. https:\/\/isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.<\/p><\/div>\n<p> \t<BR><br \/>\n <BR><\/BR><\/p>\n<p> \t<BR><br \/>\n<BR><\/BR><br \/>\n<a href=\"https:\/\/isc.sans.edu\/diary\/rss\/33018\">Go to isc.sans.edu<\/a><br \/>\n \t<BR><br \/>\n <BR><\/BR><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Possible ACR Stealer From Page Impersonating Claude, (Tue, May 26th) Introduction In recent weeks, I&#8217;ve searched for pages impersonating Claude that distribute malware. In recent weeks, I&#8217;ve reliably found these sites through malicious ads in Google searches that lead to these pages, often concealed in URLs for sites.google[.]com, such as this example from 2026-05-11. These [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[56],"tags":[69],"class_list":["post-13141","post","type-post","status-publish","format-standard","hentry","category-isc-sans-edu","tag-isc-sans-edu"],"_links":{"self":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/posts\/13141"}],"collection":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/comments?post=13141"}],"version-history":[{"count":0,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/posts\/13141\/revisions"}],"wp:attachment":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/media?parent=13141"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/categories?post=13141"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/tags?post=13141"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}