Malicious PDF — malware analysis report

Static analysis result for SHA-256 f634b4c7c33e5275…

MALICIOUS

PDF

80.6 KB Created: 2021-09-13 11:58:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7af02bdf3c0b702f42f1bcc344a1bd93 SHA-1: fb527f1672c5534ae4e495c63e2ae023112c49fc SHA-256: f634b4c7c33e52754247fdae674c3d121baf2035b30f8228ae99f0bf60e82377
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that point to compromised WordPress uploads and disposable hosting, suggesting it functions as a link farm. These links are likely used to redirect users to phishing sites or download further malicious payloads.

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://queure.ru/uplcv?utm_term=install+adb+interface+driver+windows+7 PDF link annotation
    • https://nocenzura.space/web/img/podborky/files/dedofuguxetesasojabowogu.pdfIn PDF document text
    • https://lotteppta.com/beta/assets/file/lusoxedogaxedozudavozuvi.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/pitenawoj.pdfIn PDF document text
    • http://vitalchurchesinstitute.com/files/file/83524196997.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/49519809298.pdfIn PDF document text
    • http://fskyok.com/uploadfile/files/sogedixowebuforolulisata.pdfIn PDF document text
    • https://www.sherpachristain.org.np/ckfinder/userfiles/files/63363115637.pdfIn PDF document text
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/kakiseluwakedig.pdfIn PDF document text
    • http://hortherbpublisher.com/files/upfiles/file/5480580217.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/47173910594.pdfIn PDF document text
    • http://eksternest.be/images/file/fejatulefawixodipifi.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/pexesasuri.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/tabuvexazopal.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/ae92f8c5f1bbd696e5c7933fe7a203cf/25920289639.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210907083140.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134c0e6ea8d7---xuvuwiwefovemalexu.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/40624920165.pdfIn PDF document text
    • http://lobanowscy.pl/userfiles/file/84804569559.pdfIn PDF document text
    • https://happycolaborativo.com/uploads/files/41464982940.pdfIn PDF document text
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/161320cacb7a7b---kenopasiremidusugokuvi.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/fapetesaze.pdfIn PDF document text
    • http://hydrogears.com/survey/userfiles/files/54447206190.pdfIn PDF document text
    • http://fairway.cc/images/blog/file/22619836066.pdfIn PDF document text
    • https://szallas-karpatalja.hu/upload/detozi.pdfIn PDF document text
    • http://melabo.com/upload/files/33914427440.pdfIn PDF document text
    • 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_off0000d608.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD608 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE1F 10760 bytes
SHA-256: c8b70eac0846ae4dd3ac2245cbc84f5d2f8a21ec075580df199c3bf58ee3f36d
font_02_sfnt_off0001071a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1071A 17568 bytes
SHA-256: 1391c64c6e1c675be1f26eee077ddbe22d71ba6375f0e49cff314bb4d696fd81