Malicious PDF — malware analysis report

Static analysis result for SHA-256 8820e6af7f176d03…

MALICIOUS

PDF

80.6 KB Created: 2021-09-10 05:34:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6c76576ef1dfe41ee6d25cec5d2c6ed4 SHA-1: 0146a05dee9d04ca79a448727c90cb3e8b67ab50 SHA-256: 8820e6af7f176d03c172b3b762b3a6cad919b81cd239f0a94e8397a9f6495437
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating a malformed exploit stream and a link farm pointing to compromised CMS uploads and disposable hosting. The embedded URLs suggest an attempt to redirect the user to malicious sites, likely for phishing or to download further payloads. No scripts were extracted, but the PDF structure and URL patterns are indicative of a malicious document designed to exploit user trust.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://slabowidzacy.smprzemysl.pl/ckfinder/userfiles/files/34989843101.pdf In PDF document text
    • http://aiaato.com/FileData/ckfinder/files/20210910_EBB0DEA242C9F22D.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/nejajodimuku.pdfIn PDF document text
    • https://ottopianos.nl/files/16366274977.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613088e748225---71306536463.pdfIn PDF document text
    • http://kondicionery-dzerzhinskij.ru/upload_picture/file/fusotetod.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/pexuri.pdfIn PDF document text
    • http://lmalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4527487255.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/vtja5e07ka740bgsls2it2o3v5/pidosef.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161303c5a4d1c1---95303756996.pdfIn PDF document text
    • http://dichvubaove.online/upload/files/gufirurajologotubanisom.pdfIn PDF document text
    • http://insei.eu/userfiles/files/80410792.pdfIn PDF document text
    • https://actor-conseil.com/files/file/63988716795.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/linunolarujatefabu.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/59167074508.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/29a54403641be5ae691f3df96d1ec9ac/fojim.pdfIn PDF document text
    • http://whkmradio.com/userfiles/file/zomofitoraxom.pdfIn PDF document text
    • http://www.s-prom.si/fileupload/file/96836116924.pdfIn PDF document text
    • https://sealand-pptc.com/userfiles/file/nadulabokujagotolufukoz.pdfIn PDF document text
    • http://szjg.hu/images/file/jasukota.pdfIn PDF document text
    • https://www.thaiahpa.com/flash/files/79824546223.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/d5c41254a57a00826d8a479bd6f60d72/93230867981.pdfIn PDF document text
    • http://abwplazaview.com/uploads/files/52322324432.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=android+going+slowPDF 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_off0000d93f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93F 10100 bytes
SHA-256: abd27123b2ba3038125a54b517a6f4395d56b7180c4a1aa8936cdaffc1f02f8f
font_01_sfnt_off0000ef9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9B 17436 bytes
SHA-256: a0c3f872caea8c833cd5fa4ef64eb6c7e99751369389b467d75a8112d0cfdfc8
font_02_sfnt_off00011d21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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