Malicious PDF — malware analysis report

Static analysis result for SHA-256 b34ff5c4ba754606…

MALICIOUS

PDF

81.6 KB Created: 2021-09-17 09:16:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6cb3ef6a9c6d09ad7cc0e42c68ea55fc SHA-1: 28f50643c98596bc2a79ecab5098f63829cc1eb9 SHA-256: b34ff5c4ba754606e2b53214aacfe8388527d211847bacc9835e42c66bca002a
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm to distribute further malicious content or conduct phishing. The presence of multiple external URIs and link farm heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://hnhaa.com/userfiles/tnejp/files/73893619223.pdf In PDF document text
    • http://klusjesindex.nl/images/uploads/nususugaderufu.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/93501728799.pdfIn PDF document text
    • http://355353.ru/userfiles/file/58366044608.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613df1ba1b543---70910175131.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/ec833a1824a9a36bfdeb60f0889e5a9a/37220850709.pdfIn PDF document text
    • https://digiconelectronics.com/media/gupen.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161410dc5be468---57752237838.pdfIn PDF document text
    • http://kencert.vn/uploads/image/files/99160693721.pdfIn PDF document text
    • http://wowbond.com/upload/Fckeditor/file/29528345102.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/29384913602.pdfIn PDF document text
    • https://printsolutions.ro/uploads/wysiwyg/files/gofigezezubojinepiv.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612fddb0f1f8a---65597056141.pdfIn PDF document text
    • http://pbhdom.eu/userfiles/file/wesetononunadelimuweg.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/85091301371.pdfIn PDF document text
    • http://teamhead.net/userfiles/file/60788172467.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/11982c63fa22cb84925c47247bba439f/15670664944.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///dumemer.pdfIn PDF document text
    • https://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/55339954074.pdfIn PDF document text
    • https://media-get.com/userfiles/files/9242129402.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/57280546989.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/88079494220.pdfIn PDF document text
    • http://hiroshima-teishaku.com/userfiles/file/fulad.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/98859371039.pdfIn PDF document text
    • https://globalcircle.club/userfiles/file/34811752249.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=parentskit+app+downloadPDF 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_off0000daa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA8 18052 bytes
SHA-256: 8e2f937c8b8da255dc822a0c2c95c484acbebfbef2a429acfa7e5e3d4ca8a4ba
font_01_sfnt_off000108ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108EA 10564 bytes
SHA-256: 0af7a596c46b721813565d5b89be8dd35253db8b930624f111d6050dac74a9c5
font_02_sfnt_off0001212e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1212E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1