Malicious PDF — malware analysis report

Static analysis result for SHA-256 92b434b3c44a6fee…

MALICIOUS

PDF

96.8 KB Created: 2021-08-31 03:52:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 2ece641d5d79981f8d6025c463b84fb4 SHA-1: a86e5488371fa2567dd82671567653d9b4b3efdf SHA-256: 92b434b3c44a6feee05ed1362f3c3f1a127209175fcd888f47ad29a0a411e3f9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a link farm pointing to multiple external URLs, many of which are hosted on compromised WordPress sites. The embedded JavaScript likely serves to redirect the user to these malicious links, which in turn host further PDF files, suggesting a multi-stage download or phishing campaign. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://palenice.net/obrazky_clanky/file/xagorap.pdf In PDF document text
    • https://olgunbey.com/upload/ckfinder/files/51373984641.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/9d3acc2338cf6ae1121aa2d222055690/14079792094.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/72335033620.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f267367c54f---31620879419.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608246a98d9df---vudebuwotidokugov.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/wukawinofibivukefedevas.pdfIn PDF document text
    • http://grupophi.es/uploads/files/99029029488.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/6790481434.pdfIn PDF document text
    • https://psychologgia.pl/Upload/file/pulefolapibizevutixova.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/ef8fg88inca7ug5re5ub4kn4om/fiwanese.pdfIn PDF document text
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/m89ier9vanq80iealppj4b3vjb/74319059550.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/gosedagisaba.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16129241cad5d1---43038799777.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/segadige.pdfIn PDF document text
    • http://radiofarsasch.online/upload/files/zinukevusivu.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/majarijeteleruti.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30373261038.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608a695dc15ef---mukizulexeganenoguvajum.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/881562ce383f0748f61c9c317d044f2d/futawamarunitajub.pdfIn PDF document text
    • https://reaga.net/js/ckfinder/userfiles/files/setosabirufutavenuzo.pdfIn PDF document text
    • http://archifolder.com/userfiles/files/12863009196.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086b40f9a9e0---bizawofopo.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086b3d3df802---pevatevomidubigudo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=xscf+reference+manualPDF 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_off000116ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116AD 17988 bytes
SHA-256: d4397c26800a1fe465988b0a4dc860bb48e71f0e189328424764648d59842ca1
font_01_sfnt_off000145cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015de3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DE3 10292 bytes
SHA-256: 415dfe255dbdb1356a910dc7c8a550be92a405e40fac192f4b21391cd2f2e303