Malicious PDF — malware analysis report

Static analysis result for SHA-256 635d09f1347099b8…

MALICIOUS

PDF

94.6 KB Created: 2021-08-14 00:02:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d164f3839254d7673ea573dea580bae4 SHA-1: 9be66c34488d2b87629fa4cad607a64c68d7c6c4 SHA-256: 635d09f1347099b8619aae68c03bf47e46e381d79563554da77ceec020835516
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. It contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute further malicious content or conduct phishing. The presence of external URIs and link farm indicators strongly suggests an attempt to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://stadion-zarya.ru/ckfinder/userfiles/files/64263380494.pdf In PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/4f92d68e42824fadc032c312cab9d4ad/40823132561.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/161082252eadd3---20208577437.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/bbf670719b0863913b352243248a2894/wusamunonakuninikasesoxod.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d92d48858---56973898442.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/jezopofenatitetegapabezo.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/7a113fd18bd95873383190be162126cd/42913201748.pdfIn PDF document text
    • https://bloc-immo.com/images/musatupepol.pdfIn PDF document text
    • https://lacecinella.com/writable/public/userfiles/file/putetizoxuwe.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/53019137865.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/75093417723.pdfIn PDF document text
    • http://fdscience.com/UPFILE/userfiles/files/30900568427.pdfIn PDF document text
    • https://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/4f0okaa5kcd4852jnmom2t6ugj/33336590177.pdfIn PDF document text
    • http://funperm.ru/content/file/18664084806.pdfIn PDF document text
    • https://aravlicraft.com/cmsCart//upload/file/34597095310.pdfIn PDF document text
    • http://sonarkella.com/userfiles/file/46661598813.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc850f20a0---75511267927.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/fd05a055a573bfcda797e20b7e226674/7775239010.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/47079100753.pdfIn PDF document text
    • http://studio5r.com/userfiles/files/jabuninifos.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bd0c1b0f3e---lerevegezobiwe.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/l4f6d0qvg51kciir1mom37h9o6/64606355422.pdfIn PDF document text
    • http://camonetinternational.com/files/file/wikateruv.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/ec9794bbd34d931962aefbd84e1483d5/jusuguwatonemejoxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=tom+clancy%27s+rainbow+six+siege+bookPDF 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_off00010c6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001247f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1247F 17708 bytes
SHA-256: e2a4c49c2487126c1731a00d8d15ada263b8c323157efd11cdfd66486511b2c8
font_02_sfnt_off0001520e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1520E 11008 bytes
SHA-256: a0de88193d1807f830b10cd85ca2689d3545da0cc1c5c840e0bc8a97a56db4d4