Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f7db4b00f760412…

MALICIOUS

PDF

77.2 KB Created: 2021-06-10 06:07:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 2a83b127c507571e15035bdcf4b15f4f SHA-1: 43b24e1fdee0ecb13c68df46d6112d767432ecfc SHA-256: 3f7db4b00f760412e369e1e9063cb93a86bd3f98f3233a1b71e0703be632687a
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is indicative of a malicious campaign.

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://medvor.ru/pbw?utm_term=7th+grade+maths+textbook+pdf PDF link annotation
    • https://sebazolilerop.weebly.com/uploads/1/3/0/8/130874482/304781.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488842/normal_6010ef592fde9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465123/normal_5fcf77c4e18f5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379491/normal_6054c36ad7960.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4403814/normal_60b7856ab9dc3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472208/normal_60bde4fdd8565.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449629/normal_603638689ab45.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426407/normal_6010d40e21b9b.pdfIn PDF document text
    • https://lotojenamiz.weebly.com/uploads/1/3/1/3/131381761/4214772.pdfIn PDF document text
    • https://tedunifadikave.weebly.com/uploads/1/3/7/5/137505165/genizigujazunida.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475565/normal_605dae359d4ef.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://nigezid.pbworks.com/f/duwagivokuzovizuzaxet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1c91de65-34e1-46e5-a7f3-449cd637e4f3/dotodifujilavakaw.pdfIn PDF document text
    • http://nomebazeregi.pbworks.com/w/file/fetch/144704967/lalulep.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/847d6008-5390-44f4-ae46-4f3994eeb265/coleman_catalytic_heater_511a_manual.pdfIn PDF document text
    • http://jutifakukap.pbworks.com/w/file/fetch/144483099/why_smiles_are_contagious_speech.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/83cba0d7-975c-4c4a-a2e7-8aa02f5b074d/neuropsychological_test_questions_philippines.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/88ec6e28-773b-4a4c-b2e1-92062e72362a/35571606179.pdfIn PDF document text
    • http://najapenoz.pbworks.com/w/file/fetch/144543942/13213324387.pdfIn PDF document text
    • http://jebodigezev.pbworks.com/w/file/fetch/144511344/how_do_i_write_a_simple_application_letter_for_a_teaching_job.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE47A 5316 bytes
SHA-256: 3bfc6d9a0723f6eaaa7b64b8b58116b266f68a9a5394c6e405531aefe583140a
font_01_sfnt_off0000f693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF693 10304 bytes
SHA-256: e030b94722b47427d25fe833d8005b7b897eb1bc134e89d5a00bfaa79be49f9a
font_02_sfnt_off000119c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C8 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2