Malicious PDF — malware analysis report

Static analysis result for SHA-256 86b19c8d495b3973…

MALICIOUS

PDF

85.7 KB Created: 2021-09-14 09:15:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 30404ba1762651d0d4c5e2465d15c070 SHA-1: aa89163fd7fd20ec96539e08200a47c8a306aa2e SHA-256: 86b19c8d495b39731bb02cb9b706fd45ca47c4bbcd0744904de0c758804b1c28
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to numerous disposable hosting sites. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristic point towards an attempt to redirect users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://sentezetutmerkezi.com/upload/ckfinder/files/setagijogabi.pdf In PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16136373cdcffe---ferobilimamu.pdfIn PDF document text
    • https://www.lipca.com/ckfinder/userfiles/files/vupakigonolake.pdfIn PDF document text
    • http://denprokhorov.ru/images/file/77230834448.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/10430346725.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/lowejoratefijekax.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/gipit.pdfIn PDF document text
    • http://shamayachts.com/upload/file/38860785002.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/62710883638.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/ravifesogubakuror.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f034633e54---27041198281.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/95940517823.pdfIn PDF document text
    • https://barcelonamedicalcenter.com/files/galeria/files/31039673742.pdfIn PDF document text
    • http://resumesfromabove.com/userfiles/file/73913024688.pdfIn PDF document text
    • http://soojuspilt.ee/files/file/zoxepekebepume.pdfIn PDF document text
    • http://stisk.com/file/tabapugosasinagevux.pdfIn PDF document text
    • https://trystsalonri.com/images/file/47779776362.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/5827773961.pdfIn PDF document text
    • http://cyuanmei.com/userfiles/file/88655538123.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/pipusikiboxetagajitemamu.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/tojejowirasemenelotipo.pdfIn PDF document text
    • http://beergolfers.com/blog/images/file/61172013217.pdfIn PDF document text
    • https://renesens21.com/ressources/upload/files/17511077439.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/90723916106.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=deleted+pictures+on+android+phonePDF 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_off0000ea1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA1C 17620 bytes
SHA-256: 886604ab0f363438e23fe9e498279f919d6d9da5a969963c92a288000275544d
font_01_sfnt_off00011832.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11832 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013049.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13049 10712 bytes
SHA-256: 1d1d8578f5892a00f1d9afd2fbe3db2e85f5f9a48249f04f90119c63489dbdef