Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bf2860994e18561…

MALICIOUS

PDF

83.4 KB Created: 2021-09-06 02:55:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f7976d47abb577c04844c369a2e7a4f2 SHA-1: 64870f7c3cfdc91b42a2e5a882a2781e87da0e12 SHA-256: 8bf2860994e18561f034abbe361431d843f6407617845f5048e68a3b39fda285
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, several of which point to compromised WordPress upload directories, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://vrajacreation.com/uploaded_files/userfiles/files/nukato.pdf In PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd0fa4ea86---jibebido.pdfIn PDF document text
    • http://ktcz.eu/files/files/wenoledi.pdfIn PDF document text
    • http://fredericjean.net/oplusco/file/3849439906.pdfIn PDF document text
    • http://adacu.org/userfiles/file/20210621020252.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/c89b24640b1e511b7e541c65e8171732/98395245526.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/761886625608bcdc294ee6.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1606ea7f3bfa8f---vosugigufugori.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/42556972847.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c1c0c0efe7d---wepexarowasu.pdfIn PDF document text
    • http://brezov-gaj.si/uporabnik/file/40017093441.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/81563d6d84c8b96f1f4c84f332653f25/15073398197.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/dumifutow.pdfIn PDF document text
    • https://tavio.ru/files/file/denipuvujonazebesa.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/bagabalemajido.pdfIn PDF document text
    • https://famecosmica.it/file/91453978014.pdfIn PDF document text
    • https://zegaoyun.com/calisma2/files/uploads/simobitok.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/jegesozisewapovimawinama.pdfIn PDF document text
    • http://elisa5888.com/shopadmin/upload/files/49556628434.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/161244ea8345e2---jasol.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/dirumexavud.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160897154054a4---viralej.pdfIn PDF document text
    • https://fcr-fomentoconsumoerenda.com/uploads/files/katuwalakemenubo.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/zowivikoromukoxodilunozef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=palabras+en+ingles+con+su+pronunciacion+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_off0000de2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE2A 19120 bytes
SHA-256: 9a7bc809e9985477572c38ca29326b10f01b40498ef5216250ee7900d8520281
font_01_sfnt_off00010eb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EB3 10940 bytes
SHA-256: b0498c0967702c88a1e36068addb5958b2a4c1b0c764ca3069bf22b7bd7dc18c
font_02_sfnt_off000127b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1