Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b66b8dc3a3cc775…

MALICIOUS

PDF

87.5 KB Created: 2021-10-11 20:19:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: fb460ed57404e00e55ce437b0cb84915 SHA-1: a0942515fcb29d763913afe30acfaa184821878f SHA-256: 5b66b8dc3a3cc775dcbeb5d0942adef3561ca4616411b71f4dcae2500149f320
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users. Although no scripts were explicitly extracted, the PDF structure and the nature of the URLs strongly indicate a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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://balie.overeembv-profielen.nl/upload/files/73538166102.pdf In PDF document text
    • http://notar-frings.de/userfiles/file/21850533770.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/c9e4b92b5faa1a070c4a529921d4a6e3/89048741705.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/38162963886.pdfIn PDF document text
    • http://xn--d1achljw0b.xn--p1ai/content/upload/47319792381.pdfIn PDF document text
    • http://straub-online.ch/userfiles/files/lagavuw.pdfIn PDF document text
    • http://www.pilatesyoga.hr/files/files/35444738748.pdfIn PDF document text
    • https://bulendengin.com/upload/ckfinder/files/59253814470.pdfIn PDF document text
    • http://steelfurniturecn.com/d/files/61579172984.pdfIn PDF document text
    • http://gsnursing.in/ckeditor/ckfinder/userfiles/files/nojokemusuzixodujitejimu.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613be844e94e9---93045460957.pdfIn PDF document text
    • http://daiquangsico.com/img_duhoc/files/juxovulegasevesox.pdfIn PDF document text
    • http://shukokai-voves.fr/userfiles/file/ditisizelopebel.pdfIn PDF document text
    • http://pol2-simf.ru/userfiles/file/suzemipid.pdfIn PDF document text
    • http://insuralead.com/userfiles/file/rijomesad.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/6970aaa99c5aedf1c8cf43fdbca1cc25/dolefafenip.pdfIn PDF document text
    • http://terryloops.com/E/file/81873238620.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9f84b423a---gapuxe.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/lugeb.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/tomawutel.pdfIn PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-10-1/20211001090449543141.pdfIn PDF document text
    • http://obras.ru/sites/default/files/uploads/soketiwulum.pdfIn PDF document text
    • http://paradisoseminatrici.it/userfiles/files/33103193792.pdfIn PDF document text
    • http://cy2hand.com/userfiles/45137747945.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/d616688e687698190e36bb9fc9155027/42452593172.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/oscUj7J0Gjw/uplcv?utm_term=inflorescence+of+tulsiPDF 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_off0000eeb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB3 10220 bytes
SHA-256: 0c1dbff47798147f488e32d1b85da0113cbc392f93f815946165c67a583fc501
font_01_sfnt_off000105be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105BE 19984 bytes
SHA-256: dd0b5df6b4f611ad3f130502b88dacabdc74f9202ec75e4004963a53810d4e8d
font_02_sfnt_off0001384d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1384D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1