Malicious PDF — malware analysis report

Static analysis result for SHA-256 66ea4f26ca2b7230…

MALICIOUS

PDF

80.4 KB Created: 2021-09-08 12:05:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a540afc4633093c9d90874a355cf2f84 SHA-1: ee11300d42eeb5b4bc503da1ba3de6448c7cbed5 SHA-256: 66ea4f26ca2b72303041ea50910233a7c1910c4855df1fa94cc89342085a010d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious content. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious files or conduct phishing. No scripts were extracted, but the structure and URL patterns are indicative of a downloader or phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/6alrp1iu8c3ukm1mhurbsjvrvf/51186814120.pdf In PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/lirawemevetadovewamosezu.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/2h5gr8bh0ttd3l2ip1qqsf4vql/72651914568.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/15465592953.pdfIn PDF document text
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/e15eecf2c6d0cd916cee80b4ed93c6aa/89452725522.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021051001130573499.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/ef124932783a04b3844b7b94ee22ca14/97111815741.pdfIn PDF document text
    • http://springgalleryng.com/Images_upload/files/35107148979.pdfIn PDF document text
    • https://poolpoint.be/uploads/file/37409406099.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608e049055f84---9947241984.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/sozirotuwanoteru.pdfIn PDF document text
    • http://blankheich.de/images/uploads/file/josibatoxiretunukawuzam.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/jirewinederu.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/3762f6969f81d0096252a26f5bdf9a52/dororiveninasosatu.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/10853861282.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/81484575664.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d38e06fb37---nibuvixoro.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210606032527.pdfIn PDF document text
    • https://digireg.cn/upload/miduwonenuxawikoterepug.pdfIn PDF document text
    • http://shlawllc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sufef.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/08nfj6hmn7icutb17pjn92fbu3/55540211200.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/58268955237.pdfIn PDF document text
    • http://quartierdete.fr/uploads/fckeditor/file/96996305839.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/92942801489.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//rezanibedijipamomelozojos.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606eb91827e47---94002653894.pdfIn PDF document text
    • https://www.stock2morrow.com/ckfinder/userfiles/files/pabojixesusorolututoxuji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=korean+english+hymnal+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d772.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD772 16476 bytes
SHA-256: a92ec0f3f57d021c1d87d8448af561f005ab4aa66fc048874547bad5f21488d9
font_01_sfnt_off0001022c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1022C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A43 10952 bytes
SHA-256: 2f00b81b6916f7c4d2678bfc679f34a4a81c2946303b66e588851d78c9f406b6