Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fd5dc9b16483b0d…

MALICIOUS

PDF

83.6 KB Created: 2021-09-15 13:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: acb2c8d7c031b270860d8ccf088cf676 SHA-1: da686efeb9a2f58ef43755667e70c44d613fa51b SHA-256: 8fd5dc9b16483b0d25dfc248b08f34826259ad1be4f509edc9590febc2e580b8
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous URLs, many pointing to compromised or disposable hosting, suggesting it functions as a link farm to lure users to potentially harmful sites. The presence of multiple external URI heuristics and the PDF_SEO_DISPOSABLE_LINK_FARM rule further support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://nomylo.ru/uplcv?utm_term=index+of+the+following+season+1 PDF link annotation
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/xakojofo.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/44850856602.pdfIn PDF document text
    • https://ccichn.vn/data/upload/file/9259649466.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614164a12f3b9---sujubepukovemedigozufe.pdfIn PDF document text
    • https://la-klamm.org/Files/files/falokupik.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/67097047832.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/gamiwefefenesoxilofexu.pdfIn PDF document text
    • https://aarushimukhwas.idealviews.com/userfiles/files/87076868014.pdfIn PDF document text
    • http://nuestratierrapremios.com/campannas/file/ririgenuzedodajuvux.pdfIn PDF document text
    • https://silverbirdmarketing.com/pages/images/file/52481920775.pdfIn PDF document text
    • http://compow.net/ckfinder/userfiles/files/17848608846.pdfIn PDF document text
    • http://minhphucvietnam.com/uploads/userfiles/file/96367982465.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16141a0d866a29---89366170938.pdfIn PDF document text
    • https://medbioplast.com/klucharnet/images/file/69755891086.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/lidegewamifajoxudaz.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/4155150156.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/70485970877.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141646b9def8---bekizifubirepexosiv.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/46450070645.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/ratifugilakufefam.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_off0000e2f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB0E 10724 bytes
SHA-256: 1dbd4d93840b13996f3970cad95688e37f31f17913babe09f2e911c33b9e3531
font_02_sfnt_off00011386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11386 17256 bytes
SHA-256: 0f39802664b53d89b6e0e6cb1d09ab9bb1e2ee7ac4dbf67bc295169c825e6e5e