Malicious PDF — malware analysis report

Static analysis result for SHA-256 de028739e179271b…

MALICIOUS

PDF

105.8 KB Created: 2021-10-08 11:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 527393176036044f25cc5cff38ccdb46 SHA-1: 52948962e6a1e0732c1a947efb1be2f923b23ef1 SHA-256: de028739e179271b4e751f26d7621bf3ad8484ed85ac45c7df1421bc1d057f5d
164 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were directly extracted, the presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, along with the ML and AV detections, points to a malicious document designed to trick users into downloading further malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://crewmak.ru/uplcv?utm_term=javascript+check+word+in+string PDF link annotation
    • http://ginzaramen.us/uploads/files/fapapenorufizosadamelu.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/gexutemuk.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614576091317c---11888727206.pdfIn PDF document text
    • https://hkpefa.org/editor_upload/file/35780260151.pdfIn PDF document text
    • https://kitapkapla.com/upload/ckfinder/files/28739124419.pdfIn PDF document text
    • http://drivingtesttips.ie/fckeditor/userfiles/file/41232835744.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/a4a8441a65abff78e3b8a179527e3f5d/xazatabowupefajifewelura.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1615141bc96f26---37601139066.pdfIn PDF document text
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/wunosusakajofitovivu.pdfIn PDF document text
    • http://flomojapan.com/upload/files/lawedopubon.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161373c088b142---94929701374.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614603b20db31---texudufofatom.pdfIn PDF document text
    • https://daqing-jewelry.com/uploads/files/202108311745497689.pdfIn PDF document text
    • http://machulski.com/public/file/lisiwusovutadaleferot.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/9e0ef22c09fd806d9c0dc6c03adea9ff/kegegixunef.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/gomutugixijujaba.pdfIn PDF document text
    • http://cappellastudio.it/userfiles/files/12492113576.pdfIn PDF document text
    • http://conganbacgiang.vn/app/webroot/uploads/files/xedofuruvobared.pdfIn PDF document text
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/kukakutowuzomun.pdfIn PDF document text
    • http://www.contal-farmer.com/uploads/files/kibotizeguxuw.pdfIn PDF document text
    • https://bdprescription.com/ci/userfiles/files/lamufoduzulojo.pdfIn PDF document text
    • http://opersan.com/file/1444261508.pdfIn PDF document text
    • https://netlandschool.cl/files/xiporuz.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/83264b68951850aecc755b7892af0554/vaxikovekibeliwogoxebejo.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_off00012fcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000147de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147DE 21224 bytes
SHA-256: 8fe79a25d4bd477765c5993aee2e40f563bb7331184c526055f5f947a94475d0
font_02_sfnt_off00018023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18023 10980 bytes
SHA-256: 7fdce38643573fa061daaa6ce1eb246e8cb17a4c9865f56dbff378237b7c2478