Malicious PDF — malware analysis report

Static analysis result for SHA-256 50c77ac23bd03703…

MALICIOUS

PDF

72.8 KB Created: 2021-09-18 07:55:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1097c6fc5a2e4fdc51f1350649014e89 SHA-1: 1919efe63c56c4bc4944e053387c4683dd78cac1 SHA-256: 50c77ac23bd037035fb326e2a790141a1f575cd0dee51b939f565634990da292
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, with the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicating a pattern of linking to many distinct, potentially disposable hosts. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The sample's structure and URL patterns point towards an attempt to redirect users to a network of sites, possibly for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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://ndmoyun.com/calisma2/files/uploads/vidusapomogukixomosox.pdf In PDF document text
    • https://spvi.cn/filespath/files/20210916223247.pdfIn PDF document text
    • https://www.elshandmadedesign.nl/ckfinder/userfiles/files/vaxigefariparatuxeju.pdfIn PDF document text
    • https://magiccat.pro/ckfinder/userfiles/files/85404840404.pdfIn PDF document text
    • http://mid-europe-ex.com/images/blog/file/20759260977.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/89457249959.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/32112564211.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/dupifizimukavatu.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/38962312385.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f60014fcd5---polukogelazepu.pdfIn PDF document text
    • http://sms-dk.com/FileData/ckfinder/files/20210917_CB04B753639AE0BA.pdfIn PDF document text
    • http://keralabiblesociety.com/fck_uploads/file/putejoregolexivi.pdfIn PDF document text
    • https://7mark3t2-7aya.com/contents/files/54681622440.pdfIn PDF document text
    • http://cycling-software.com/files/file/sopusovuxudi.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/75289924171.pdfIn PDF document text
    • http://nguyenxuanhuong.com/upload/files/81777174034.pdfIn PDF document text
    • http://kantoromega.pl/userfiles/file/63980327708.pdfIn PDF document text
    • http://fatfailogistics.com/fckeditor/files/file/fiditomaloduzilu.pdfIn PDF document text
    • http://librojuridico.com/aym_images/files/52430770057.pdfIn PDF document text
    • https://vzglavniki.net/data/file/80609640683.pdfIn PDF document text
    • https://agros.net/uploads/file/48360209014.pdfIn PDF document text
    • https://nexapos.com/upload/files/rovabimizixefolenopu.pdfIn PDF document text
    • http://millecolori.it/images/file/83750400448.pdfIn PDF document text
    • http://robertfeinberglaw.com/images/edit_images/file/ruvaletatukilatomulolidaw.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/41612404157.pdfIn PDF document text
    • https://jecoexports.com/ckfinder/userfiles/files/mumuvodepagolox.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/84268037619.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143aeec7ab81---zazipiwakimibi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=cactus+mccoy+3+hackedPDF 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_off0000b804.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB804 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d01b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD01B 10804 bytes
SHA-256: da7d8896a60aea936bd8823617a8de4c090f1f6f0a9f69f0a31922355cc92122
font_02_sfnt_off0000e927.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE927 16992 bytes
SHA-256: 823200ffc970298fc586519a56cf5e9d3e581e9ce96d252f3fe1d392797fddc9