Malicious PDF — malware analysis report

Static analysis result for SHA-256 b476d78e58c7f69d…

MALICIOUS

PDF

73.7 KB Created: 2021-04-22 12:03:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 267ebc93ad3f6738d38be21f1a5358a1 SHA-1: 27ef79ba51f7dc5864f217595ae2120ef26d2dec SHA-256: b476d78e58c7f69df23f190f14a886166345b27740f35888637e9a6d2f5f60b9
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 hosted on disposable domains, suggesting a link farm or phishing operation. The primary malicious URL identified is vilenefex.ru, which is likely used to distribute further malware or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vilenefex.ru/strik?utm_term=possessive+nouns+practice+online PDF link annotation
    • https://widegavadiwudux.weebly.com/uploads/1/3/5/3/135325068/e65b859de5f74f4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375200/normal_60533e634b64a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467586/normal_60532f12a7ddf.pdfIn PDF document text
    • https://jejomedilad.weebly.com/uploads/1/3/5/3/135316302/8300311.pdfIn PDF document text
    • https://tajamopem.weebly.com/uploads/1/3/4/7/134745730/8937653.pdfIn PDF document text
    • http://sellamorem.com/252342046643tn55.pdfIn PDF document text
    • http://community-day.ru/amelie_sheet_music_piano7ns9d.pdfIn PDF document text
    • https://zogetomobosuzo.weebly.com/uploads/1/3/4/7/134741576/d18e849bb.pdfIn PDF document text
    • http://file-id.ru/555953196383tg5h.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/dowadotiju/star_wars_canon_novels_chronological_order.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6774c1ff-89bb-4a5a-8fa0-21ddf768e942/p90x_chest_and_back_video_stream.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/699b8a2c-6c95-4473-8d38-b5feb2a5ef59/microsoft_project_online_essentials.pdfIn PDF document text
    • https://s3.amazonaws.com/kalanejaxutilif/58317377024.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/34b0f271-8aa7-43df-91ad-9ee58113adce/what_is_human_computer_interaction.pdfIn PDF document text
    • https://s3.amazonaws.com/wupagivoz/neturuxeni.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98371a63-e951-4c7e-a109-147fce9df88f/how_to_improve_functional_fitness.pdfIn PDF document text
    • https://s3.amazonaws.com/faxaxos/69060773720.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdfd0167-d4d3-4c4c-8c7d-d9a8f53e213b/how_to_get_the_hiking_merit_badge_counselor.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1228ae6a-face-44c0-aef8-9fea2ca2116c/hp_designjet_500_driver_windows_10_autocad_2016.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d0942cc4-3b63-4020-b8fa-dfc8fd3b971c/23513245944.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/43942991-a49e-4212-a325-88aac2adedd1/how_to_exercise_with_one_dumbbell_at_home.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d0fb80c4-78cc-4e3b-8be3-3425dc8e5e0f/asus_z170_deluxe_motherboard_specs.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/31dd7aa0-2745-43fb-92f2-3c75b41d2050/pigonewemexapabozeb.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_off0000e31f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE31F 4988 bytes
SHA-256: 6cce2ac4c690af62473da7359f49328cfc95affd2e63d7f0f6b621440c309d40
font_01_sfnt_off0000f42d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42D 10992 bytes
SHA-256: 90935a1e3c4648c1e3235f66ceb1315bc0970df2537c04e8ee5b7f70524ccaa2