Malicious PDF — malware analysis report

Static analysis result for SHA-256 9873027bf36dce80…

MALICIOUS

PDF

87.8 KB Created: 2021-09-07 10:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a37fcfb9b080d623c79cd51a07b64072 SHA-1: 77f1c64266ffae6282821f3ff6e174045df78f33 SHA-256: 9873027bf36dce8066284bd112e07c2464236d011702d8f03b25b6e92b246723
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs, many pointing to compromised WordPress sites or disposable hosting, forming a link farm. These links likely lead to phishing pages or further malware downloads, indicating a malicious intent to deceive users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://queure.ru/uplcv?utm_term=prime+and+composite+numbers+quiz+pdf PDF link annotation
    • http://haozuowenwang.com/imagefiles/file/6130918617.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c5bb0b04e---25160352479.pdfIn PDF document text
    • https://xn--faade-mtal-p6a3a.ch/ckfinder/userfiles/files/56731355484.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a863d2f3260---xesekel.pdfIn PDF document text
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/fbcd660d59472657878877d613421533/49544600314.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/gapotonemog.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160966e01857c6---xosujigadilugofazu.pdfIn PDF document text
    • https://digireg.es/upload/debugipolalupi.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/28284908275.pdfIn PDF document text
    • https://almuhja.ps/ckfinder/userfiles/files/78266557215.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c89e387a35c---68164125004.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bee79826152---21594684996.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/c6281acbeab8f4656aa8f8b041672ad1/77426695578.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/90b06792d1d511a1e6d677cad2b3c880/fagudu.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/fadodime.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c443bde8b---90585957307.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/11422489730.pdfIn PDF document text
    • http://zonwering-nederland.nl/ckfinder/userfiles/files/masusagebexunolosasek.pdfIn PDF document text
    • https://brakos.it/file/93120246436.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160b8e88b86005---vagibokubipemepibetev.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/5abc59da1907edc11b5a94c2d4f75126/vigovekizirap.pdfIn PDF document text
    • https://doktor-ara.com/userfiles/files/benexurab.pdfIn PDF document text
    • https://hoangnhataudio.vn/media/files/43738774395.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160718949c666f---22143537600.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_off0000eaad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAAD 11184 bytes
SHA-256: 4434ff4f7fcc5e8acd94198545f2707c02b1d3c2fa417ba3f160b2f7a7af0488
font_01_sfnt_off00010464.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10464 20332 bytes
SHA-256: 0d57734728c9e0e24786160d7e7d5c2f24e89b4c18b875c783a8e6d36ba5df8c
font_02_sfnt_off00013944.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13944 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1