Malicious PDF — malware analysis report

Static analysis result for SHA-256 1afeca1ff4dc2079…

MALICIOUS

PDF

75.6 KB Created: 2021-03-23 19:00:43 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 43ed6e1dbf1b2fcf64a8f4d2f0a250cf SHA-1: 2c30e7ce5f540416bb3e720e7410fbbe586dca57 SHA-256: 1afeca1ff4dc2079867d0ca1d33e9d93a87d4b4d0bf73dcafd208a0b8d6d6030
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to disposable domains or are used in a link farm strategy. The heuristic PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM indicate a non-standard use of PDF for SEO manipulation, likely to host phishing or malware. The ML classifier and ClamAV detection strongly suggest malicious intent, with the primary IOC being the suspicious URL on xajibur.ru.

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://xajibur.ru/strik?utm_term=kinetics+reaction+mechanisms+and+potential+energy+diagrams+worksheet PDF link annotation
    • http://shoop-fr.ru/256491989698n2wp.pdfIn PDF document text
    • http://ubzvp.com/rise_of_african_nationalismyehqw.pdfIn PDF document text
    • http://lavka-karamel.ru/pdp_xbox_one_controller_not_working923x7.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/555b9ce6-4f08-453f-b519-07b15050d261/82234751650.pdfIn PDF document text
    • https://d04c2b29-3777-4fe6-aaa9-ab96f87c3324.filesusr.com/ugd/43eb95_602aa19b2f8243949048c6f4237cad40.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a74292f-c4d6-4707-8467-063af8789e6a/91994629721.pdfIn PDF document text
    • https://s3.amazonaws.com/petikamov/gegalojapadidusefu.pdfIn PDF document text
    • https://s3.amazonaws.com/pazerogasarinu/doctor_appointment_booking_system.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/66100114-5cc6-4e1b-981e-41e4ab97504e/65184765619.pdfIn PDF document text
    • https://s3.amazonaws.com/zurovajij/handball_match_report.pdfIn PDF document text
    • https://26c1613e-5d28-4fa3-89cb-3d2c9ab59faf.filesusr.com/ugd/fe83c3_95a9f5938f0a40a8b2b0c8eb8630a034.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/423f2621-6b49-45cb-a903-272a45ddbb3a/38968711712.pdfIn PDF document text
    • https://14535e1a-360a-4d01-a655-fa33e115c80e.filesusr.com/ugd/b222ea_ceb4f6831f824123b824283714955b76.pdf?index=trueIn PDF document text
    • https://6fc76513-a17a-4053-940d-bef108f5ea85.filesusr.com/ugd/3a5ef0_9895eeef0d0341b89fcc3cd572455b80.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f60657dc-d194-4194-bfac-47196f120416/sobitizos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b8caf55-924c-409f-b0d5-9874b146d934/online_quran_reading_16_lines.pdfIn PDF document text
    • https://s3.amazonaws.com/metubevozisul/business_expenses_spreadsheet_excel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a17e7b15-be2b-4d43-89cd-58063328a749/sowufexomi.pdfIn PDF document text
    • https://s3.amazonaws.com/lawakux/french_michelin_guide_in_english.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/31a32d3c-8312-4944-b78a-62cfc3281436/57100700019.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/04df500b-6e81-4b05-b0fc-7904291cbce3/read_diary_of_a_wimpy_kid_meltdown_for_free.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_off0000e83d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE83D 5712 bytes
SHA-256: e031f1aee252d44d1e6e74fabfff347710b473a0e04fb0ecee0de28addc7c8c2
font_01_sfnt_off0000fba5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBA5 10796 bytes
SHA-256: ba8f8e971244d9ffde20f413260c0b216404a6ec425ebe7bde18aea1a2e8dc20