Malicious PDF — malware analysis report

Static analysis result for SHA-256 5815c85639e3144f…

MALICIOUS

PDF

69.0 KB Created: 2021-09-27 17:33:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0b66b032d5cbce2eb287141cd8bd5b72 SHA-1: 139a04ec5244d27680bfa547007ece7baabb45da SHA-256: 5815c85639e3144ffe370ba207ed12154a71f2a2b4dd973d562a68bd3936e52a
126 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan payload. The PDF contains numerous embedded URLs, many pointing to disposable domains, and exhibits characteristics of a link farm designed for SEO manipulation. While no scripts were explicitly extracted, the PDF structure and the presence of external URIs suggest it is designed to redirect users to malicious sites, likely for further exploitation or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://noahmission.org/dataroom/file/15391818609.pdf In PDF document text
    • https://stvietnam.net/luutru/files/30862160213.pdfIn PDF document text
    • http://archiw.gbpopatowiec.pl/img/upload/files/sokawanuvunuzal.pdfIn PDF document text
    • http://www.serge-valentin.net/ckfinder/userfiles/files/dexiforatijotogos.pdfIn PDF document text
    • http://melvin.cz/data/74129556587.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/mikapatan.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/9d66429a5fc90e7125529a4e8e4309a3/86524823154.pdfIn PDF document text
    • https://matharu.ae/userfiles/file/lekanalabixexavovu.pdfIn PDF document text
    • http://timeyear-v.com/userfiles/file/73535020308.pdfIn PDF document text
    • https://amgaa.org/temp/files/5667384630.pdfIn PDF document text
    • https://biroestarsa.hu/uploads/file/rawomogu.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/81646775d0741a8917226b33e36b0fe6/81919459255.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210908155412.pdfIn PDF document text
    • http://border-collie.ru/sites/default/files/file/wedapuzefutuwazurufogu.pdfIn PDF document text
    • https://totalsewa.com/userfiles/file/77504800560.pdfIn PDF document text
    • https://h16hr15k-h19hr37urn.com/contents/files/98799901051.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/bojigisetegenibu.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/78719208663.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/fukajimakaxitojureso.pdfIn PDF document text
    • https://fengshan-zhennangong.org/upload/ckfinder/files/balufib.pdfIn PDF document text
    • http://com123.vn/uploads/file/58398827303.pdfIn PDF document text
    • http://miyisz.com/mingyi/images/userfiles/file/62011322058.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=pokemon+dark+gba+downloadPDF 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_off0000ad4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD4E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c560.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC560 16208 bytes
SHA-256: c2e947af704238c5b8f1c547a8d4e870991ce282d1fa93d594eab68d72e437db
font_02_sfnt_off0000eee6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE6 10552 bytes
SHA-256: 0f6f468ebb26099c79c989ce70b589b3c2c938423fd62a16de965d98b86482b9