Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6d837de253952da…

MALICIOUS

PDF

77.9 KB Created: 2021-09-22 23:48:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 829c1b41460047bde1dcd0f3d1fef42e SHA-1: c63302b14485a745229f2a79dfd3dac3087c32d1 SHA-256: f6d837de253952da2782b100022676284eda5b38c59457bab8f868654f3ce219
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and a machine learning classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URIs, including one pointing to a link farm, suggests it is designed to redirect users to potentially harmful content or phishing sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the idea that this PDF is part of a campaign to distribute malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://archism.ru/uplcv?utm_term=recover+vaulty+pictures PDF link annotation
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/b023dfdf0f5c0fbbeebafc8c30312ab3/30419654914.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/70454867928.pdfIn PDF document text
    • https://dellrein.ru/content/file/sukibuwokedesuki.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/13244658389.pdfIn PDF document text
    • http://yung-shun.com/userfiles/file/35936281226.pdfIn PDF document text
    • http://cokhihoaiduc.com/uploads/files/finakadatofizi.pdfIn PDF document text
    • http://pazzo.jp/js/upload/files/xegogarawudafasun.pdfIn PDF document text
    • http://imoroz.by/upload/file/13017221965.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/16131873ddc8be---74866103444.pdfIn PDF document text
    • http://4226080.kad.tw/kads/ckfinder/userfiles/files/jojowuzojilomof.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/kibofufoxatimigano.pdfIn PDF document text
    • https://somogyplusz.hu/files/91257314075.pdfIn PDF document text
    • http://mnogonomerov.ru/uploads/file/49573237367.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/95385365492.pdfIn PDF document text
    • https://institut-arabe.org/ckfinder/userfiles/files/26785459360.pdfIn PDF document text
    • https://andreivieru.com/ckfinder/userfiles/files/61997724716.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/jumijinalokopumifaw.pdfIn PDF document text
    • https://hogies.com/includes/template/uploads/file/banekumojexobiwud.pdfIn PDF document text
    • http://gostinica-domodedovo.ru/files/vojutomel.pdfIn PDF document text
    • https://o-dance.com/upload/files/zuwajezugejepo.pdfIn PDF document text
    • https://livre-art.com/ckfinder/userfiles/files/12213956879.pdfIn PDF document text
    • http://szpk.hu/_user/file/bixojutowokibijobipexomog.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee8c9ed4e0---19249875410.pdfIn PDF document text
    • https://kamwalibais.com/userfiles/file/79431967190.pdfIn PDF document text
    • http://dolekkoyum.com/admin/UserFiles/file/volewanap.pdfIn PDF document text
    • http://fields-on-earth.com/images/blog/file/kikidumotutuxupo.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_off0000cd7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE590 17288 bytes
SHA-256: 7ad535544cb97fed90138ab36264f2e9c3b2b5398d169b5e38b4040dedb6742d
font_02_sfnt_off000111a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111A0 10588 bytes
SHA-256: 1302db8e13040732b4f39435050618cbb61d15c28073282a99a84cac9b596e7e