Malicious PDF — malware analysis report

Static analysis result for SHA-256 87b77c9e2b4ea693…

MALICIOUS

PDF

86.0 KB Created: 2021-06-26 09:01:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6b2dd4617961725ec6ede966dc7551e7 SHA-1: bfd22e69991523d187558292086526d65da7d285 SHA-256: 87b77c9e2b4ea6934c164c61c40819518d78d9c292602bc897bfd51867827617
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse. The presence of multiple external URI heuristics further supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://agnieszkapawlik.com/userfiles/file/wuzewevases.pdf
    • http://musorcentrum.hu/files/article/file/tuluvitejogibugosa.pdf
    • http://thepnguyentran.vn/media/ftp/file/ximumuwezifopifimepaj.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c14ab8b73ef---49469403315.pdf
    • https://celebicatering.com/upload/ckfinder/files/13572558713.pdf
    • http://cowmoo.org/ckfinder/userfiles/files/gozabigimolebaxepikiv.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9e638b789---47083659293.pdf
    • http://rkmaster.ru/uploads/files/sipidunadukaxag.pdf
    • https://isleo.com/i_photos/file/66023277053.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a57bc0ead16---74077615383.pdf
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/aolf030lbrqkues9bc1of1bvag/nokinokefifedirop.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160accaeb1c747---61169213911.pdf
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/9466654d91f973d82e5243d5076d7db5/53491466020.pdf
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/db39ce1464ee21cd9fbeca4529685b7e/39957909146.pdf
    • http://gocreate.termall.pl/upload/fck/file/vovosoxafifiki.pdf
    • https://edarky.net/data/file/zubajawolavigobodiwuvubi.pdf
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609ccb211fb20---25370560927.pdf
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092c259ac900---18402679759.pdf
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/t2eetbo3l997e0353s94rfgsdm/xediwakigabovepeworu.pdf
    • http://aisef.org/uploads/userfiles/file/file/76871069142.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160841f24eb087---95233356918.pdf
    • http://cleangroupbd.com/ck/upload/files/60140370314.pdf
    • https://shriayurvednagpur.org/public/ckfinder/userfiles/files/93790175259.pdf
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/34a9e9aedc9ab803ed7f15871906566c/kubadidivorewolenafesi.pdf
    • http://aj-logistics.com/stock/userfiles/file/sibosopijojaxabalikedol.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=why+is+venus+called+earth%27s+twin
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed6d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED6D 16792 bytes
font_01_sfnt_off00010584.bin
542eb74fd04f1ebf67fd93d4b449b097a4bf0793c0d21d85287845edc0d0ab4f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10584 10740 bytes
font_02_sfnt_off00011e40.bin
36084034e8c91862c631d37638e979e091bfbe6b1fb4b613206612113a7b3da7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E40 17224 bytes