Malicious PDF — malware analysis report

Static analysis result for SHA-256 3615cdf25942e8eb…

MALICIOUS

PDF

73.3 KB Created: 2021-06-20 04:14:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 4bdf381ce9b0dfdbe9fc4f68b6a44c87 SHA-1: 29906621b920db607298070dcabb028b9bf40c04 SHA-256: 3615cdf25942e8ebcf2a6686f3cf7e3366adf2a157cea8a7c421563989f2fde8
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of external URI heuristics and link farm indicators supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://chetanaus.org/bheru/uploadfiles/file/44496037082.pdf In PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/acog57r1m5thgki0cnc72ghb7o/67421623450.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607e722de6752---5359087682.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/nafalafitof.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16087527f79fda---55260684366.pdfIn PDF document text
    • https://moto-trend.cz/public/files/fck/file/84795720553.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/adf21af6a85cb70ab903012a268a4e2a/39612432279.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/6tr1k0ulrodl3pvfb5kaoqv74c/toginidajezu.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c4549e9d922---giduk.pdfIn PDF document text
    • http://wenxuezj.com/images/File/xositofumusirugeloso.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a349f074a6c---16859607603.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/c984886ea8d124bb7cd340736dddef84/xuxumagemekuru.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b00fb12cd1---takipudagatajivup.pdfIn PDF document text
    • http://bright-inter.com/file_media/file_image/file/15536762492.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/2201f65d765653851bc8af4ee8035b64/24531465639.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/387fb1ccf1464d93609bde827f7894db/vadafexatokewebegubuzukip.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=snake+and+ladder+game+rulesPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e226.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE226 5312 bytes
SHA-256: a0c462e15aaed07b3353a9a7cab23893af70436464c479aadb47ce174a199b57
font_01_sfnt_off0000f41e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF41E 10624 bytes
SHA-256: b18ffd33bdaae069c7bad59b78ebc1d591ca9f27701d55df54f70db0ebd013f7