Malicious PDF — malware analysis report

Static analysis result for SHA-256 b51b102e81d29236…

MALICIOUS

PDF

130.6 KB Created: 2021-09-02 20:15:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 863f790b32a11b2a0cc4def6770fb2a2 SHA-1: c85208cdcb4727c415634fbae8fafc8f4dd66c78 SHA-256: b51b102e81d292369bbab4d09458224226e0f107920c2c6f3b7fd450fddfc020
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Analysis revealed a link farm structure with numerous URLs pointing to compromised WordPress uploads and disposable hosting. These links are likely intended to redirect the user to malicious content or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

Heuristics 6

  • 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.
  • 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://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088c97c95a07---61656530938.pdf In PDF document text
    • http://terhautz.com/upload_files/files/vebatogev.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/maxaribunejozekeluj.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160d97f53b893d---22430332155.pdfIn PDF document text
    • http://ipublicity.cz/data/file/64574423555.pdfIn PDF document text
    • http://verduciautodemolizioni.it/userfiles/file/fexarixezodifasexa.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/d779bc0fab291fa6e729e9cf4279533f/gagodidanajigap.pdfIn PDF document text
    • https://abouelhoulgroup.com/userfiles/files/11719739662.pdfIn PDF document text
    • http://euredit-editions.com/userfiles/file/62342788317.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/ketujusujudod.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8f65b133e---vesez.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/jbci1f6br9tv7pbd16rhbm8luh/natowikatoguxobetaku.pdfIn PDF document text
    • https://southwestlooms.com/admin/userfiles/files/reputogozatuv.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608310050a028---31720153733.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/dojogimakejagiloropufi.pdfIn PDF document text
    • http://polipadel.com/userfiles/file/zugojevawirosemuleninu.pdfIn PDF document text
    • http://biplano.eu/userfiles/files/29983932051.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/160ed124509fbc---43851639750.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcfc77e58d6---62256653521.pdfIn PDF document text
    • http://holzweiss.at/59009850774.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/a80u042o7kqea1anfbs9vcano3/tuwovezesewobu.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ed84e62750a---vibadokebifilofoj.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b0e0151e8e9---26042440821.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=char+broil+tru+infrared+grill+manualPDF link annotation
    • https://mediaget.com/userfiles/files/88596580801.pdfIn PDF document text
    • 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_off00019348.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19348 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001ab5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AB5A 21356 bytes
SHA-256: 185801921322d4a9d93f2149696d2ef9a06cd9358b58113be62ff8fc9e938ec9
font_02_sfnt_off0001e36b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E36B 10904 bytes
SHA-256: 18d63271a2afdc249b71401986314549122ce41d215eec094ef38ecc11a33271