Malicious PDF — malware analysis report

Static analysis result for SHA-256 79b66dce4d34f1ea…

MALICIOUS

PDF

70.6 KB Created: 2021-09-11 15:50:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 444d90d6a0d8bdd549965df31478b2a3 SHA-1: c0e864edb1376ac9bc9b52260db4ee8d726ab641 SHA-256: 79b66dce4d34f1ea0754d6a21c546da03213cc356a26b18fc2bbfa226b998c5d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many embedded URLs pointing to potentially compromised or disposable hosting sites. The primary purpose appears to be directing users to external, untrusted websites, consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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://ffarchitettura.it/userfiles/files/21759908826.pdf In PDF document text
    • http://sungsam.net/userData/board/file/legalozo.pdfIn PDF document text
    • http://togul.org/sites/default/files/file/10097233977.pdfIn PDF document text
    • http://doingthing.com/downloads/blog/geust/files/89964713199.pdfIn PDF document text
    • https://thebottombillion.org/business_school/uploads/file/xixujokenubuga.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/sg3ugu4oif8erdv8kpns7lail6/jowebefedikelazotos.pdfIn PDF document text
    • https://investmentskillsgroup.com/images/userfiles/file/15243513318.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/33250354501.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/depusupegubari.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161306963ecc40---rekonumefuketalafigowor.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/lemagodibunaned.pdfIn PDF document text
    • http://cka-shiba.com/ckfinder/userfiles/files/26975543279.pdfIn PDF document text
    • https://mytshirtcreator.com/app/webroot/files/file/rebubudujolitexuroguratad.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/logememukubogowutadiba.pdfIn PDF document text
    • http://ekonopuntos.com/campannas/file/wezafixuwunifibexumej.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/wipupevugizovew.pdfIn PDF document text
    • http://tianlanlawyer.com/filespath/files/20210902111737.pdfIn PDF document text
    • http://exima.kr/userData/board/file/jefiwokagotexar.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/86730946801.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/57242334580.pdfIn PDF document text
    • http://centreforeffectivecoaching.com/media/file/betaxivibamoxunirus.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/daputuzobimuzefixaxesina.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/f8iq8cadeqmlr0m58h8te0lurv/fibodanogejaxe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=hamlet+english+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_off0000b475.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB475 10716 bytes
SHA-256: d79e666debd0426aca93f00d96ec36073a37931056d0352a4f64edb27528a34b
font_01_sfnt_off0000cc8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8C 15864 bytes
SHA-256: e91215e688cfc00aa264ccb2b0d34168f12eef122d4439664e7e1293846613d8
font_02_sfnt_off0000f4c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1