Malicious PDF — malware analysis report

Static analysis result for SHA-256 36ef589b62c7c326…

MALICIOUS

PDF

85.6 KB Created: 2021-10-06 05:01:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 27c9d347a4e6810dd26a825cbe4cfd48 SHA-1: fe61b1f3160efac9aec0372c7299ee8a5a2107bc SHA-256: 36ef589b62c7c3269b73e3a6ca9b03203968f5c3bde543e88ce4e6f95be1fc43
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm pointing to numerous external PDF files. The presence of embedded URLs and the structure suggest an attempt to redirect users to potentially malicious content, aligning with phishing or malware distribution tactics. Although no scripts were explicitly extracted, the PDF structure itself is often used to host malicious JavaScript or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://dreiseengrundschule.de/files/tadinaxorodimufa.pdf In PDF document text
    • http://toroisg.com/public/images/files/jegunopodowosumiv.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/18299780513.pdfIn PDF document text
    • http://www.hgekc.com/media/userfiles/file/57276531055.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/92597255755.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/54224103789.pdfIn PDF document text
    • http://arabstina.com/ckfinder/userfiles/files/64002091698.pdfIn PDF document text
    • http://turismo-usa.com/files/others/nenamudozom.pdfIn PDF document text
    • http://yuhenganquan.com/userfiles/file/20210925010326_1767567275.pdfIn PDF document text
    • https://praktijk.zorglink.nl/ckfinder/userfiles/files/bimimifarese.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/90131818845.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/mifilexosoxurowobisir.pdfIn PDF document text
    • http://mpti.ru/userfiles/file/gipowategosewipajif.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161302a11b89c7---82612482834.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/nufuvuzasukuju.pdfIn PDF document text
    • http://casaatlantida.com/userfiles/file///mufikagiwafetezunani.pdfIn PDF document text
    • http://medicalproduct.hu/images/files/lamifulokiworigugezud.pdfIn PDF document text
    • https://sukhayurveda.in/userfiles/file/34838985215.pdfIn PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/bunijozefasu.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/39389774753.pdfIn PDF document text
    • http://sabaparsian.com/ckeditor/files/files/kefabagulopozadimigujeker.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/sidilunegojoxov.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/tekatitufidopemizukijafu.pdfIn PDF document text
    • http://allivecoat.com/userData/board/file/66826445184.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/maxogerudotekusi.pdfIn PDF document text
    • http://tianlanip.com/filespath/files/20210906231759.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=rigatoni+with+sausage+and+kalePDF 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_off0000e599.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE599 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fdab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAB 19516 bytes
SHA-256: 99c94a72b29f48bcc40b7723ed0734f779b7237a032164aea3b1a380dbe6da93
font_02_sfnt_off00013018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13018 10748 bytes
SHA-256: 69f4e7aab99ac4902f0423ae5ac937330ac2bc59f4154ff35c7dad51cab68965