Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbd102711895f030…

MALICIOUS

PDF

69.6 KB Created: 2021-10-02 10:51:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1a581d943c249fb5fb1986f427fa230d SHA-1: 70e58516a16d5031a9667f30fdf45cca499e0102 SHA-256: cbd102711895f0304891a83741c45cc78d8d9ae8ad308a6a25caf61133ac8144
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised websites or disposable domains, indicative of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple external URI heuristics and link farm indicators reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://cructi.ru/uplcv?utm_term=school+club+interview+questions+and+answers PDF link annotation
    • http://maraulsan.com/ckfinder/userfiles/files/75822636312.pdfIn PDF document text
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/78725851074.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/tufibo.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/tefefaxelew.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/83dbacad32c05fd71cc11cbfc66865d7/34382062435.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/37636267896.pdfIn PDF document text
    • https://xn----7sbeo1acdy3adh.xn--p1ai/userfiles/file/porokoxinevinevatemivo.pdfIn PDF document text
    • http://homelife-superstars.com/image/files/82158619374.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16141d372ed384---taxipebixelaxugetesik.pdfIn PDF document text
    • http://quesnelbusinessnetwork.ca/userfiles/file/ribibowibemedi.pdfIn PDF document text
    • http://skpizzasubs.com/uploads/files/wilotir.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/papeb.pdfIn PDF document text
    • https://webmanagement.jbclub.ro/images/file/28889972780.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/tedagipetugevogog.pdfIn PDF document text
    • http://jagodkaprzedszkole.pl/userfiles/file/xagemomago.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614ee1b54aeb4---litufobizafowe.pdfIn PDF document text
    • http://kondicionery-himki.ru/upload_picture/file/buxevoxajibod.pdfIn PDF document text
    • http://contextuae.com/resimler/files/deranubisuz.pdfIn PDF document text
    • http://master-br.ru/img/file/32682400685.pdfIn PDF document text
    • http://digitalpolicycouncil.com/imagenes/file/52836441795.pdfIn PDF document text
    • http://lubrifianti-auto.ro/files/file/nefobawimumuj.pdfIn PDF document text
    • http://herfon-machinery.com/images/ckfinder/files/20211002005108.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/ledukasirakusepafijuj.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_off0000b11a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB11A 15056 bytes
SHA-256: bed4e822a763e3cc6ed379b1e15831069c886795faf28181fb753170a47d69f7
font_01_sfnt_off0000d698.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD698 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eeaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEAF 11080 bytes
SHA-256: 5b1c498b7217f73ab3b8ee267fcd4fee22485a226c8772edf2f0631046d5c32b