Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c92ae3909322fc5…

MALICIOUS

PDF

82.5 KB Created: 2021-09-20 02:16:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 864378c1c8f7f5dc01c983dbf8837c78 SHA-1: 03148e353e28805df9a92ce41424662ea7f8a0ec SHA-256: 8c92ae3909322fc53a2e494cb7e11858cad5695bd6310be568f80a535831b9f7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which are structured as link farms on disposable hosting, suggesting a phishing or malware distribution scheme. The presence of external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chcial.ru/uplcv?utm_term=modern+family+season+11+gomovies PDF link annotation
    • http://nerezove-kuchyne.cz/UserFiles/File/64455888524.pdfIn PDF document text
    • https://zahrek.com/userfiles/file/munoradowaxizizev.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/venalugap.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/30312448025.pdfIn PDF document text
    • http://yibetter.com/data/files/7985486257.pdfIn PDF document text
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/xetuxuvetomaderoxerowifu.pdfIn PDF document text
    • http://retailpark.bg/uploads/wysiwyg/files/85838654576.pdfIn PDF document text
    • http://zsmnowakowski.pl/userfiles/file/kesemokuwarom.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/jowasil.pdfIn PDF document text
    • https://www.opsclown.it/ckfinder/userfiles/files/bukama.pdfIn PDF document text
    • http://areawifi.com/DESARROLLO/userfiles/files/4123307176.pdfIn PDF document text
    • http://vodnik48.ru/content/file/wopusojozezadina.pdfIn PDF document text
    • http://ncdesign.it/userfiles/files/rizoputilen.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d5b267d2f---29208223711.pdfIn PDF document text
    • http://weilandensemble.nl/ckfinder/userfiles/files/pivosudo.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/51069244559.pdfIn PDF document text
    • http://oikoscoccatoarchitettura.com/userfiles/files/17900921115.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/mukifojatigoxoviwepabuxo.pdfIn PDF document text
    • http://bobas24.pl/Upload/file/2582277945.pdfIn PDF document text
    • https://carcable-bg.com/uploads/pictures/files/12076434626.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210909163205.pdfIn PDF document text
    • https://vaitinhdien.com/app/webroot/upload/files/mukotitotanabikod.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/xipiwanidodudulexegojegid.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/161371c2331261---fusabuxurevabe.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_off0000dcd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD0 10824 bytes
SHA-256: a8ce7686fb3290a7c9b6e5395d2490f6cb618ada5bd0085940f9206b7051fc96
font_01_sfnt_off0000f59d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF59D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010daf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DAF 18164 bytes
SHA-256: 7b24ca29b7dc8ffcebb459c5e4583484e54f86f6437021596d8b6ba91812bef3