Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ac33ff439ecb42a…

MALICIOUS

PDF

75.8 KB Created: 2021-09-03 03:47:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 4af7e1c3f09f004b5acb6c9ccc33c073 SHA-1: b61ef0835d4b9d6d6b654a6207e721a3720001fb SHA-256: 9ac33ff439ecb42a11d3873a3b3a8fde62f5439bded94aaec58ee60169858fd5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript is a common method for exploiting PDF vulnerabilities or initiating further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://best-label.com/upload/files/tudodigasale.pdf In PDF document text
    • http://webdulich.com/js/ckfinder/userfiles/files/jewewegol.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/wapopipozixama.pdfIn PDF document text
    • http://orthopaede4you.de/userfiles/file/fakaboguzisuj.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/dujaf.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/nawuxi.pdfIn PDF document text
    • http://fujiya-burbank.com/uploads/files/nulatubetozason.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1608af2674900a---39100532433.pdfIn PDF document text
    • http://beveragesgs.com/userfiles/file/wufofoxogimokutome.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161238c9ac8c2d---razopidabipuk.pdfIn PDF document text
    • https://dehayemek.net/upload/ckfinder/files/notizuverupewez.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/uli995sactcr2cp2p8u8jroei7/xorotiforivatufol.pdfIn PDF document text
    • http://zetrade.cz/userfiles/file/36711218884.pdfIn PDF document text
    • http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/72651742909.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/fa2l7agvoj4hevg9ee6l6q30l1/bepodosanusesedifok.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcd8c68850---31072004834.pdfIn PDF document text
    • https://sukaunited4d.vip/contents//files/76759179482.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608fcde39d03c---65065105578.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=analysis+of+machine+elements+using+solidworks+simulation+2017+pdfPDF 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_off0000b765.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB765 20188 bytes
SHA-256: 750d89b3a1ca8f1ea1858c88a85830fea4992875f64105be477c9a31701c18b5
font_01_sfnt_off0000eb98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB98 11784 bytes
SHA-256: fec0c7e99bdd1ed5dfa45e677fc6a640ce2eece301cd93464f51357f0edc154f
font_02_sfnt_off000107a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1