Malicious PDF — malware analysis report

Static analysis result for SHA-256 91cd2afaa75f3b27…

MALICIOUS

PDF

71.1 KB Created: 2021-09-08 17:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cbe16d55c2d040eab9aae56464071911 SHA-1: de71d3dc29cfd7b57577f2e56db5de121ae8cec2 SHA-256: 91cd2afaa75f3b276034fcfa8b3bb3a633c03487180100bc541830393ff722c9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous embedded URLs, many of which point to potentially malicious domains, and one heuristic identified it as a link farm on disposable hosting. Although no scripts were explicitly extracted, the nature of the PDF and its embedded links suggest it is designed to redirect users to malicious sites, likely for credential theft or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://spc1991.com/ckfinder/userfiles/files/6209211261.pdf In PDF document text
    • http://wohntraumgmbh.at/makugelapivupigew.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/83995276408.pdfIn PDF document text
    • https://designmaster.in/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/87646770747.pdfIn PDF document text
    • http://olivetheater.com/userData/board/file/35510985726.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/27441915128.pdfIn PDF document text
    • http://yourhealthyanswer.com/ckfinder/userfiles/files/40423549752.pdfIn PDF document text
    • http://olympusflights.com/files/files/zefusin.pdfIn PDF document text
    • http://hftyby.com/upload_fck/file/2021-9-2/20210902195923313019.pdfIn PDF document text
    • http://swvocal.com/data/se2/file/89008361448.pdfIn PDF document text
    • http://metallpress.info/files/kuwanomafadet.pdfIn PDF document text
    • http://www.cerel.eu/images/wyswig_images/file/51481346855.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/rijevetekizemafav.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/bizitutewo.pdfIn PDF document text
    • https://hoangphatdanang.com/uploads/image/files/32706625066.pdfIn PDF document text
    • http://spellenindex.nl/images/uploads/ginevojivirawutaxoj.pdfIn PDF document text
    • http://cheapmarkt.com/userfiles/file/zefifakajesotapitubafev.pdfIn PDF document text
    • http://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/83290596243.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7938768c1---valagewarowemi.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/4021876643.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/1129743718.pdfIn PDF document text
    • http://ge-mak.com/files/72698226935.pdfIn PDF document text
    • http://www.sun-green.eu/ckfinder/userfiles/files/97229811345.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/jitogagidibotuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=sum+and+difference+of+cubes+worksheet+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_off0000b418.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB418 11332 bytes
SHA-256: 73d75b7c3fe42f18f30915d0584b85e6972012fab7ac2b366343b3d0a52de659
font_01_sfnt_off0000ce66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE66 15972 bytes
SHA-256: 6def040ccc29306c717628ae00ca2dc801b33dcc9635c77022931313ce80c730
font_02_sfnt_off0000f6e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1