Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a131d7384e19ac8…

MALICIOUS

PDF

92.1 KB Created: 2021-06-17 20:06:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: fad51c4f36935f5c6a188bd2d45aa05c SHA-1: cd6808203c1c5feb3260599951bdd5f482757128 SHA-256: 4a131d7384e19ac84bbb3834ce2ef73582560796609cd4f0267810a00aba42f6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'German volume training benefits', which may be part of a social engineering tactic to direct users to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://medvor.ru/uplcv?utm_term=german+volume+training+benefits PDF link annotation
    • http://brucemsmithlaw.com/clients/e/e2/e252bfde01ef004f685a9648d307a4b9/File/tasamanazobi.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8fda00d669---pubimagoxugitixusixukani.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160afcd828d67b---tosaputafesi.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/29eaa8644a927e9cdcafaf3fbb6dab13/77348414348.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aba366a1d06---60012254363.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/c92e6e6b207ecf9d032471b082146adc/43257801939.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/kaxowabimitusatake.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16087c69e47901---vafijipe.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/q73rdvie9j9m2iavuqer0s1ukv/10503869319.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/rj5ev03kv0kivjua25hmu1kp4j/26490659418.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e3c7c604cd---beredokara.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/1dfa379e8595d3362c5a8104c802c1a6/2659110258.pdfIn PDF document text
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/853234e73c179003df04bf0bb183d908/bovetuperejubufitaj.pdfIn PDF document text
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/1cf1b1c2bc40ae70f235c11b54cb5ea1/wakadelikime.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca84092e5a9---zobufegomepipa.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012aed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AED 5316 bytes
SHA-256: 99df84cdda42020ec28d8a36b423420b9b784f0a71e044c49656bfdf4a4b8fe0
font_01_sfnt_off00013cf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CF5 11160 bytes
SHA-256: 246d510eaae875aa11265cc09bd3e8141689866655cbd20b1c67332dc9625d33