Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c4d73b7fea14aa9…

MALICIOUS

PDF

75.1 KB Created: 2021-06-03 10:40:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: d8110c64159d9b165cb91c28051bc84e SHA-1: eb962ec5fec87cd9d5df91c875a4b2a9ac1c7359 SHA-256: 8c4d73b7fea14aa94b7fee94e8ca413aee59fee9761c2e45880aada9767329b5
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 of which are on disposable hosting or use UTM parameters, indicating a link farm for SEO manipulation or to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the PDF structure itself is indicative of a malicious lure.

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://nomylo.ru/pbw?utm_term=comparative+and+superlative+adverbs+exercises PDF link annotation
    • https://vowopazi.weebly.com/uploads/1/3/4/0/134096587/xumuru.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386073/normal_600a61b7256a2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374703/normal_6021855ed82da.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4372383/normal_5ff07c0288217.pdfIn PDF document text
    • https://sapixokevabose.weebly.com/uploads/1/3/4/4/134498139/sunemi-rurojugo-latazifanim.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465149/normal_6002a700b3c0d.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/5a818bad-0261-4397-9634-78c8f43f251b/legal_terminology_book.pdfIn PDF document text
    • http://fatakalewene.pbworks.com/f/muxemajiwesewafuximexig.pdfIn PDF document text
    • http://vogituvu.pbworks.com/w/file/fetch/144495504/photo_to_video_maker_software_free_download_for_windows_10_32_bit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/400120a0-4676-4abd-b258-482ffd10379c/keriginewepegijarana.pdfIn PDF document text
    • http://dejulagimu.pbworks.com/w/file/fetch/144534168/90823535823.pdfIn PDF document text
    • http://joraxakegeg.pbworks.com/f/angard_staffing_holiday_request_form.pdfIn PDF document text
    • http://zubipuwaf.pbworks.com/w/file/fetch/144505389/kikoruzujabolur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/adc7a6a0-c75b-456a-9214-1ded4cd1ad10/oscar_et_la_dame_rose_chapter_4_summary.pdfIn PDF document text
    • http://xojifot.pbworks.com/w/file/fetch/144423600/moxanapapukiseporewekere.pdfIn PDF document text
    • http://moxulolo.pbworks.com/f/detepilinigibevulubupaje.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/46a8df5d-8120-4677-bd11-ea3eda3d5f33/23907876358.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8318b467-2b8b-48d0-8c60-eef2772687a8/quimica_la_ciencia_central_12_edicion_gratis_espanol.pdfIn PDF document text
    • http://nozobitativi.pbworks.com/w/file/fetch/144552534/free_personality_test_lion_otter_beaver_golden_retriever.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/573f7b5e-e93c-49e9-8978-558d802d3d87/manual_stampante_hp_deskjet_f4580.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_off0000e632.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE632 5392 bytes
SHA-256: 01f7ff9775cb25047ec67035d86915ec790ef7946dce2ab9823aa04a65eed775
font_01_sfnt_off0000f869.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF869 11300 bytes
SHA-256: 677a1b87dce00c7f86bb8c9880a9291368a295dee6b45944adc10a95404c785f