Malicious PDF — malware analysis report

Static analysis result for SHA-256 7851294428da7e6b…

MALICIOUS

PDF

94.3 KB Created: 2021-08-01 13:55:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 4c897dd5570b204763a8c3190d064047 SHA-1: 7af3ab0e5f99ce02a86f000a0040da26a860fb24 SHA-256: 7851294428da7e6b2de153d4c423cf98404f0bf0a591152a9c05e1229bfae3c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm used for phishing or malware distribution. The presence of embedded URLs and the overall structure strongly suggest it's a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://smidgel.ru/uplcv?utm_term=discurso+para+brindis+de+quince+a%C3%B1os PDF link annotation
    • http://ya-ke.cn/admin/upload/tozifeworubiza.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/94151179415.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160773a5b7b9cc---93088015174.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/r10o132s67tv6eqdimhot5do52/52772349378.pdfIn PDF document text
    • https://faprosid.com/file/1367848936.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/48406602126.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/31261108836.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/jklohc5ubg563g1qd8jcsp7141/ferub.pdfIn PDF document text
    • https://bdcomunicazione.it/file/43644121433.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5b4ecc1cd---ratuvo.pdfIn PDF document text
    • http://savoie-outils-coupants.com/ckfinder/userfiles/files/ruzitazune.pdfIn PDF document text
    • http://bollywoodsalonskokie.com/admin/images/file/fepafipole.pdfIn PDF document text
    • http://hainfelderteich.at/2436973341.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4efe3cfe9---13146097697.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4711d0b79e46f716519a025f9521af05/25752934657.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/77243546722.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c67c3d577a8---55024828934.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba524c722a---6155108521.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/37821021294.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/zovubazavonudini.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/96183385061.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/2c71a6b536e60457ee05d5d8d33884cd/74387894162.pdfIn PDF document text
    • https://ksuskalology.com/images/file/49290045061.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_off00010b4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B4B 10956 bytes
SHA-256: c239f616b865ed11dad43d544c1cea59119f91a4bcef596e68e05e5be6a7d4a0
font_01_sfnt_off00012412.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12412 18064 bytes
SHA-256: 1f9375563767d4812b8de40b39615cc9c516b1e27b5f004f77f3e94b71e0a6a8
font_02_sfnt_off00015142.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15142 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1