Malicious PDF — malware analysis report

Static analysis result for SHA-256 5520755ae03c325a…

MALICIOUS

PDF

76.0 KB Created: 2021-03-29 17:26:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: b6d82f2c35c2760e1b546dc07a3337f0 SHA-1: 1af8f2ff9c2a8fbc0880e33e58d2155c41aae1fb SHA-256: 5520755ae03c325a6f4c0012b517f98c31ec0cd2afebafd451f7ff103e0509ab
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, suggesting a link farm designed to distribute malware or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to educational worksheets, which is a common tactic for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://jumiwimov.ru/strik?utm_term=perimeter+area+and+volume+worksheets+pdf+grade+6 PDF link annotation
    • http://blue-tick-central.com/twilight_new_moon_soundtrack_downloa36o3w.pdfIn PDF document text
    • http://tufofol.medianewsonline.com/76067864350.pdfIn PDF document text
    • http://tiktokcopyrighthelpteam.com/can_you_drive_alone_with_your_permit_in_massachusettsvqr42.pdfIn PDF document text
    • http://kogutojoveso.mywebcommunity.org/what_is_the_setting_at_the_beginning_of_araby.pdfIn PDF document text
    • http://bridgecommerce.com/environmental_science_a_study_of_interrelationshipsf0bxz.pdfIn PDF document text
    • http://sevastopol.sale/gukuvebulanewufivgog8w.pdfIn PDF document text
    • http://hargotel.xyz/how_to_make_soap_using_coconut_oil_and_lyedcy42.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gubadif.myartsonline.com/bivarepokipu.pdfIn PDF document text
    • http://levapoloj.onlinewebshop.net/fedozifuwexum.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/171a3dc7-e54a-48ad-b96c-3c3c9f6aaab6/15134282341.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc022179-d44e-40f3-ac69-249d96b09ec2/pawagoragowoj.pdfIn PDF document text
    • http://bixozebaxikapos.atwebpages.com/besobuwamosadijuzelodi.pdfIn PDF document text
    • http://zesafemumibow.myartsonline.com/damituzerodekamaxo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d6a35fb8-b52e-47f6-bae2-21e5cbf0e1c4/american_standard_furnace_model_numbers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aefb732c-1c39-49e5-808e-37556f900267/55786671115.pdfIn PDF document text
    • https://8f6f9f04-f977-4239-955d-f6aecf2dd879.filesusr.com/ugd/81cd61_e79bc97b3c824470986fe6ba491f3550.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a07d5b4a-4c2c-44ce-9c11-7044d03ee4dc/vadakitabuzanawuwurelevar.pdfIn PDF document text
    • https://6f8cb219-4830-455d-9ced-b55e65700e85.filesusr.com/ugd/fd30ac_a5f51467bb0d4e82a304b32c13f221b4.pdf?index=trueIn PDF document text
    • https://f98f40d2-b649-4e6b-99af-b89bbf2331ff.filesusr.com/ugd/724bd4_af0fecf78ae742a38bfa72d92652752d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f9a0318-b48c-4bc5-af05-52db3e3dcfc3/q_see_camera.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/640b73ed-b3a2-4ad7-964b-3eec39df4e27/gevafofubomib.pdfIn PDF document text
    • http://nabafutig.myartsonline.com/how_to_calculate_speed_of_alpha_particle.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8fb60ea-4da9-4a02-82a6-09cb3fa30ddd/how_to_write_a_fiction_story_anchor_chart.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_off0000e809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE809 5828 bytes
SHA-256: f10d612ff739ce8e4904b36676b065898c8b10dd9513e949383efd78d271aba2
font_01_sfnt_off0000fbcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBCB 10656 bytes
SHA-256: 5a449ba1c5865f1c82ff14b07f07bd7990df86115458da58b4b10553a2562cc8