Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8947927682221f8…

MALICIOUS

PDF

87.8 KB Created: 2021-07-14 04:45:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0de9dbb7921c9c84b40b567a4896ef90 SHA-1: 0f1655218abec6d60ae1600d1bddf0d7edfbde29 SHA-256: c8947927682221f852f4c68634dc5870f75207a881ae210ddadf8544ebde5bfc
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains numerous links to external websites, many of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics suggests an attempt to obscure the true destination or leverage SEO poisoning for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/4v12pe5lvk7segdsica0d410qj/68773306362.pdf In PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a5bc355fec0---82127385638.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a64c4604afe---noguworuvuvitobisepuro.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/649e14cb79aa690ed5844bd232568bbd/63249521593.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160ed27d81e76f---sitinenefizid.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607523ed4638f---pikukaz.pdfIn PDF document text
    • http://smclassof57.org/clients/34860/File/69403548250.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/xorudusodegufod.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/sovededimirogonivekuned.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c0e2d9391c0---27425829212.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/83697577099.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/12246980437.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160df360a095e7---44300749013.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a04ccee4e92---niboxajudexuporibewima.pdfIn PDF document text
    • http://painttechvina.com/webroot/img/files/gikozixugobajibesil.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/307dcd4e08652db359bd6cea9be253c2/fikekenarelelupuj.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/83537372010.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609a757ca7da0---51323974882.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/tojerakasasakozodipaki.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16073fc82032c4---30411850870.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/9898431a0f919558125b93a559f71693/lubevexeponuz.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/ge2a8rc843qp8vbo8mehng8831/xasesojed.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160975bade8340---wugewipu.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef352eaa10---falepezutanobezatuva.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/saveruloladeridono.pdfIn PDF document text
    • http://rheinmotel.com/userfiles/file/52826833226.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/xufuragugoboxokokelid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=example+of+optical+diskPDF 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_off0000f2df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DF 17708 bytes
SHA-256: 2a3d1383443c03d4699da8eb77c7347e46a71793096f1b82f846d74f6404aa90
font_01_sfnt_off000120f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F6 10752 bytes
SHA-256: 16115b09d7f14fba8b4f31dcaff4243de00dd63f13edf7e0abca81096f027e54
font_02_sfnt_off000139be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1