Malicious PDF — malware analysis report

Static analysis result for SHA-256 81271c4334dd8f77…

MALICIOUS

PDF

76.0 KB Created: 2021-09-07 11:12:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 1cd44f066bcf2e5ad417e8710ad2a86c SHA-1: 5553278302e5fd41d2e79939bed7df24c3b01f83 SHA-256: 81271c4334dd8f77f2a5b02947babd9cc3b4b40f33ac1ce81fa15c5a5a057e5c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and link farm heuristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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 http://mnarch.it/userfiles/files/29891431516.pdf In PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/81393650780.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1608f1a3a32b68---kamixemoroxurerapexo.pdfIn PDF document text
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef8ed063a4---robiworewe.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/50288772792.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a445103a032---19769536229.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/zaboxipitabimanelaw.pdfIn PDF document text
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/37442228851.pdfIn PDF document text
    • https://autotrans911.com/thread/admin/uploads/file/zajudebabodogazanafed.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ad3a08954b4---wuzaxafixer.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e12979a47a---kujoditowuzomege.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/59624880859.pdfIn PDF document text
    • http://madveras.com/ckfinder/userfiles/files/mazewolaluko.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/1d5a34cf7c95a8f53f9f6a1860da67f0/rulovuwujifezoxovuj.pdfIn PDF document text
    • http://www.sphotobooth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071e72f2d818---worukatiwo.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/b843ebde995496b1d45cdfe53e4635cf/vemagudelabegimaru.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/9d447ebf67fd60ca919a3b5df3539398/51961071656.pdfIn PDF document text
    • https://havanic.com/cache/fck_files/file/47169727860.pdfIn PDF document text
    • http://cipetbhopal.com/webimg/files/damunipanukuf.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607855ac94212---xosupiretikujawulebe.pdfIn PDF document text
    • http://ratchadatitan.com/UserFiles/File/vuwageraxefifazetesibuguz.pdfIn PDF document text
    • http://quiltingacademy.info/fckeditor/userfiles/file/sezoxidipobe.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/wijelixumoxuro.pdfIn PDF document text
    • http://fenotropil.ru/userfiles/file/sujotokigigigowiz.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/7971359643.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/41273076480.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tirotenovedupupunu.pdfIn PDF document text
    • http://edmo-cars.nl/images/file/6345086000.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=wolfram+mathematica+tutorial+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_off0000c6d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6D5 10704 bytes
SHA-256: bb0c15b8dd9ab3361f1745225dd0539250ab62c68fc1b55db5fabb9785c7ee8b
font_01_sfnt_off0000df59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF59 16436 bytes
SHA-256: 61d9a4d700b0aa60e8561ffa6e9b02138a13eed8fd2ffa9411c7d342da4b43e4
font_02_sfnt_off000109bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1