Malicious PDF — malware analysis report

Static analysis result for SHA-256 665e51af55ef3d06…

MALICIOUS

PDF

85.2 KB Created: 2021-09-10 07:02:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bab4d75ee972ed5dec58a44dea58937e SHA-1: 625787ec9d59b7147ba646583e848f2b46d5478d SHA-256: 665e51af55ef3d06a3414891d365e0a97cde460b70d3aadb64f25d7e165a31d6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external PDFs hosted on various domains, with many identified as disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were directly extracted, the structure suggests a link farm designed to redirect users to malicious content, potentially exploiting PDF vulnerabilities or serving as a lure for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://elpijisystem.com/file/jinapusago.pdf In PDF document text
    • http://gddfboiler.com/uploads/files/lamaxomiwut.pdfIn PDF document text
    • https://qatarsecurityservices.com/public_html/userfiles/file/5953859491.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/81540706158.pdfIn PDF document text
    • http://saigonford3s.com/uploads/2021-09-08/images/files/38211698011.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/51416851816.pdfIn PDF document text
    • http://paletydozahrady.cz/ckfinder/userfiles/files/59000740148.pdfIn PDF document text
    • https://jjpremiers.com/files/gadibegubagoxexinepupibod.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/81810489413.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/72744865065.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/wuponirarufof.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/69419938902.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/43032452122.pdfIn PDF document text
    • https://bomnuocebara.com/quangbasanpham/app/webroot/upload/image/files/6597798228.pdfIn PDF document text
    • http://datong-travel.tw/upload/ckeditor/files/20210910114931.pdfIn PDF document text
    • http://udokutscher.de/gfx/userfiles/files/62097287375.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/ziliwa.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16137199957ae0---zowufajogugoz.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/83910373945.pdfIn PDF document text
    • https://bdata.vn/upload/files/xarerafasinisamubakoluvi.pdfIn PDF document text
    • http://medianet2000.net/amm_prod/image_news_popup/file/venavatevitiwerovix.pdfIn PDF document text
    • http://eaas-journal.org/survey/userfiles/files/pamizelokojewowimujupaf.pdfIn PDF document text
    • http://chothuexehochiminh.com/userfiles/file/wamolasid.pdfIn PDF document text
    • http://jjsgreatescape.com/uploaded_files/userfiles/files/jujazojosixawaruliledilu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=miles+morales+game+for+androidPDF 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_off0000eaf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001030b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1030B 10592 bytes
SHA-256: 8b97c951ff44c241bbf3e522fa830482b60f1d748ef975bb4a91d57c578822b5
font_02_sfnt_off00011aec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AEC 17172 bytes
SHA-256: cfc31918bd4d1dc35aabb3055a29d53225cb775b2827296d8a74c58d5bcb5fdd