Malicious PDF — malware analysis report

Static analysis result for SHA-256 b18e99503b022628…

MALICIOUS

PDF

79.5 KB Created: 2021-10-13 06:06:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 416c7f593615c9c18d1abd53bbdf12f5 SHA-1: 0bc864096f9653afceaf12cc3dca94832970ec9b SHA-256: b18e99503b022628789785e22a82b50b3fee018268151bcaa88c1202d66bbd64
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with one specifically flagged as an algorithmically-generated URL. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or trojan distribution. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support this, suggesting the PDF acts as a gateway to malicious content hosted on numerous domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 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.
  • 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://philabc.ru/uplcv?utm_term=railway+group+d+challenger+book+pdf PDF link annotation
    • http://egyptlance.com/userfiles/file/94517530892.pdfIn PDF document text
    • https://www.paseppe.gr/ckfinder/userfiles/files/xetikubo.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/tatafuzu.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/27820841575.pdfIn PDF document text
    • https://cryptobasics.biz/uploads/files/94843770085.pdfIn PDF document text
    • https://botroul.be/uploads/27918562711.pdfIn PDF document text
    • https://www.miotsukushi.or.jp/system/ckfinder/userfiles/files/wiwedinalujelujagugep.pdfIn PDF document text
    • http://protok.pro/upload/files/saxosokasowaroxinuvexa.pdfIn PDF document text
    • http://fkm-lux.by/var/upload/file/fikemokisedofigita.pdfIn PDF document text
    • http://educaholistica.com/resources/img/imagesck/files/xetujamemeko.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/31542751277.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/95692956015.pdfIn PDF document text
    • https://wegofa.com/userfiles/file/87148462604.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///2512497376.pdfIn PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/mofev.pdfIn PDF document text
    • http://mvsexpo.ru/admin/ckfinder/userfiles/files/komagafupizeminuratenu.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/51042276448.pdfIn PDF document text
    • https://psicologopsicoterapeutaemdrtorino.it/uploads/file/78545045252.pdfIn PDF document text
    • https://wct.goldcrownresort.com/magazine_files/files/35905951169.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/66357354214.pdfIn PDF document text
    • http://clainvest.pl/userfiles/file/betojebitudiladekanen.pdfIn PDF document text
    • http://budaors.varosom.hu/userfiles/files/madopa.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/96942168515.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1418263ee---75088009001.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_off0000cc04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC04 19404 bytes
SHA-256: 146b7b2a6f3e7048427da5530cf46c2502c83851c8fb8e5013b1442b7cbcac46
font_01_sfnt_off0000feb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116CB 11208 bytes
SHA-256: 9e765f6dfc241417371d796accbffca1432d8f912b86d71b5cf4fa5a877069d9