Malicious PDF — malware analysis report

Static analysis result for SHA-256 db473a2669fce9ee…

MALICIOUS

PDF

73.6 KB Created: 2021-09-10 22:19:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c4ead30b1d4baafb04e1f8af373f14ee SHA-1: 1e06a1854ae50316f202ac3416db29a70f09d01a SHA-256: db473a2669fce9ee38bff8786a1eb4073ac600bfd92b470542a799fdf5dfa28c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to disposable domains, indicating a link farm designed to obscure the ultimate destination. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's part of a phishing campaign, likely using embedded JavaScript to facilitate redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://quanghuydulich.vn/img_duhoc/files/tewakikenimatuzuk.pdf In PDF document text
    • http://condominiobrisasdelnorte.com/userfiles/file/77635240692.pdfIn PDF document text
    • http://avision-italia.com/userfiles/files/bagivuf.pdfIn PDF document text
    • http://1mosref.ru/ckfinder/userfiles/files/44657088429.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/37904686371.pdfIn PDF document text
    • http://sieuthimaynhapkhau.com/upload/files/sejexafiseruwexasalisij.pdfIn PDF document text
    • http://geasit.it/userfiles/files/ruzuwebe.pdfIn PDF document text
    • https://innotek.vn/uploads/news_file/mijupepasavato.pdfIn PDF document text
    • https://gulf-rope.com/images/bulk_images/files/timipugipisuludebo.pdfIn PDF document text
    • https://futurefacesnyc.com/uploads/file/nawazitusafubuwoku.pdfIn PDF document text
    • http://www.brickchamber.com/ckfinder/userfiles/files/wovaf.pdfIn PDF document text
    • http://chongthamphucthang.com/images/news/files/suwolawonekudozowexonada.pdfIn PDF document text
    • http://qcfloor.com/userfiles/file/gajodowovukedobexedaniked.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/57009447289.pdfIn PDF document text
    • http://pmke.cz/pictures/files/bafusawatitotawuvijagajoj.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/kojapokoruremarosekalusa.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/dogalokamidogudovika.pdfIn PDF document text
    • http://pamatudarbai.lt/ckfinder/userfiles/files/72990303663.pdfIn PDF document text
    • http://xn--h1agcmh.com/ckfinder/userfiles/files/wetukirez.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/xebiv.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f80d50f8b0---rarafuwa.pdfIn PDF document text
    • https://horgaszvelem.hu/ckfinder/userfiles/files/54763450206.pdfIn PDF document text
    • http://buren-kompanie.de/userfiles/files/47824454732.pdfIn PDF document text
    • https://www.jnvhardoi.org/ckfinder/userfiles/files/67993492491.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612e986a8b40a---85389134035.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=things+fall+apart+pdfPDF 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_off0000bd37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD37 10488 bytes
SHA-256: b639ee945db17739319a8908858f9c87a33bee9e8b7876ed2aa679a51bdfd42d
font_01_sfnt_off0000d4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B1 17288 bytes
SHA-256: f6bddc85becd6ed621a661130dbc8c5b973bcaaa4f8053d8cbb3a760c0915b97
font_02_sfnt_off000100ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1