Malicious PDF — malware analysis report

Static analysis result for SHA-256 87c673e7717b4884…

MALICIOUS

PDF

87.2 KB Created: 2021-06-08 02:50:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 1f252e870b629b8b0f39094b4b0f4c90 SHA-1: ea6730444968d5486ba6c1569c757d4bb6f59313 SHA-256: 87c673e7717b4884d25fee307e6de5535cd405272d4fe3aa32fcd11e2e70f0aa
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or distributing further malware. The embedded URLs, such as https://dafemum.ru/123?utm_term=fungiform+papillae+and+taste+buds, are key indicators of the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://dafemum.ru/123?utm_term=fungiform+papillae+and+taste+buds PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4445531/normal_5ffc116f57744.pdfIn PDF document text
    • https://bomovote.weebly.com/uploads/1/3/5/3/135398027/lejaba-wavinip-fifalabav.pdfIn PDF document text
    • https://zaluzukefajol.weebly.com/uploads/1/3/5/4/135400247/fddba5c19.pdfIn PDF document text
    • https://larezonisu.weebly.com/uploads/1/3/0/7/130738889/de40fe0ac302f.pdfIn PDF document text
    • https://fuvetozexogix.weebly.com/uploads/1/3/0/8/130874326/6639446.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4485576/normal_60b19069c7758.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447098/normal_601de56a34f77.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/3dbe766d-5b72-4388-bfd4-0715d6aa3b80/bululepulami.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e07f2645-741b-45b4-9a5d-458f5c88ee64/pufaporemovefikok.pdfIn PDF document text
    • http://wizepexu.pbworks.com/w/file/fetch/144825135/memiguvalusiket.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/267abf18-31ff-4054-914e-81983aff6108/6412559481.pdfIn PDF document text
    • http://palejemevat.pbworks.com/f/tutorial_adobe_premiere_pro_cc_2015_bahasa_indonesia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2943589f-d23f-44ee-81e8-02596048a6a6/how_to_check_awr_report_for_performance_issue.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da90ee08-fe85-4d48-84f9-2a17514aea03/dls_hack_profile_dat_free_download.pdfIn PDF document text
    • http://zalemofe.pbworks.com/f/kafotisola.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4865305b-743a-48b4-8359-d45f57f930e2/champion_generator_4000_oil_type.pdfIn PDF document text
    • http://kevuxezedila.pbworks.com/f/74440965938.pdfIn PDF document text
    • http://wojipag.pbworks.com/w/file/fetch/144661425/zozebaxudiratox.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5cfec741-4962-4a78-a0b2-a7f83b7717d2/3113786076.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/acc86bb9-c4a5-4377-9cf6-960d93878f99/introduction_to_the_theory_of_computation_second_edition_solutions.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011461.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11461 5456 bytes
SHA-256: d85f8ce32f9a17fd454b95f7026fe70b2258aa2656b5617a547c3f59a0015ad2
font_01_sfnt_off000126d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126D5 12236 bytes
SHA-256: 43bcf2cb0d77831048a8f0e0ddb51ee293e3fc813a8a449a033444a78071ba30