Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf254fe45d8c5147…

MALICIOUS

PDF

71.3 KB Created: 2021-09-29 01:38:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 408f3f7d6fab6c128c7c7682d6ac3863 SHA-1: 889ba78ff9d0da435a6d21aa311a42a1778b74f9 SHA-256: cf254fe45d8c5147c4613d3a31c6a07631abeb4b12c519488165efe296ae3f25
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to external PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM further supports this, indicating a strategy to obscure the true destination. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://aonetreks.com/uploads/file/10789768821.pdf In PDF document text
    • https://emartdeko.pl/galeria/file/94456289307.pdfIn PDF document text
    • http://24horasnoar.com.br/ckfinder/userfiles/files/rajavageriwijibikuxexen.pdfIn PDF document text
    • http://autothudo.vn/upload/fck/file/68904720758.pdfIn PDF document text
    • http://renovfab-menuiserie.com/userfiles/file/82920284835.pdfIn PDF document text
    • https://suma.ca/upload/editor/file/28366057383.pdfIn PDF document text
    • https://www.aifimm.it/admin/inc/ckfinder/userfiles/files/41353609882.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/61216842652.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/70473594724.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/44436385786.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/luzapabozosagaw.pdfIn PDF document text
    • http://servis-hradec.cz/files/file/peduwi.pdfIn PDF document text
    • https://rwd1.thadv.com/upload/files/turugegi.pdfIn PDF document text
    • http://campingwithconvenience.com/files/files/fabelidonip.pdfIn PDF document text
    • http://pokemom2.com/uploads/files/pisixesamalefe.pdfIn PDF document text
    • https://geneolock.com/ckfinder/userfiles/files/fumowajiwolotukukarapiwer.pdfIn PDF document text
    • http://hindustanadvancedsolution.com/t/tutorfirm/uploads/ck/files/tuxoxugusavumi.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/69a62981a14377a7007135862f509a29/motupezine.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/boxiw.pdfIn PDF document text
    • https://riwg.in/userfiles/file/80219897113.pdfIn PDF document text
    • http://askaudit.ru/price/dufulag.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/5af905982c27724e3614399ab5a99c32/96043887763.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/sonov.pdfIn PDF document text
    • http://myflora888.com/ck_files/files/70764243156.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=the+courage+to+be+disliked+pdf+freePDF 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_off0000b25e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB25E 11092 bytes
SHA-256: 1a021bf19898883f9a8f270dddc907b3e13cc3d546f23a3d56770cb9f40f24b4
font_01_sfnt_off0000cbf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE407 17084 bytes
SHA-256: ad5c5f6eae24dc710c2f85f64474838215b3d5568a9fbc58e1ea97ba989c93a6