Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2b16cff4a8084ba…

MALICIOUS

PDF

77.6 KB Created: 2021-03-17 07:41:09 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 1f1192525431ff62a8fb07b92e28b47a SHA-1: 28f6b015800bcd2fdede824788aab17715aa992a SHA-256: b2b16cff4a8084ba7a303e48a6579e986e118b08d3b3767e623c7c99c42b9969
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, with many pointing to disposable domains and potentially malicious content, as indicated by the 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs point towards an attack pattern designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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=ask+the+dust+cast PDF link annotation
    • http://pifemukopisare.sportsontheweb.net/concise_encyclopedia_of_computer_science.pdfIn PDF document text
    • http://fijixedi.22web.org/what_does_f1_mean_on_kenmore_elite_washer.pdfIn PDF document text
    • http://sapufawo.iblogger.org/rovafojowawigole.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/zurovajij/rotuvasitipefuwo.pdfIn PDF document text
    • https://160e4e15-e27a-4ef2-9b26-f67fc0969a86.filesusr.com/ugd/cbdbb6_9e92c55f9e9843a6887200167f0e37f3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/66c1ea64-5cd2-420c-a46d-7d584c4bdee3/how_long_to_cook_frozen_sweet_potatoes_in_air_fryer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4608513c-6ba9-4bd3-adb8-27a98b4cd01c/pdf_the_oxford_dictionary_of_english_etymology.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f03e8f9c-8587-4234-a415-c4b79d77ab4c/lawasuvijadunezagupidolad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a58af045-99ab-4465-84cb-ce964cc63cda/14871695341.pdfIn PDF document text
    • https://s3.amazonaws.com/zuvovoxigumuz/19039101600.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cba3c013-4470-48ef-93a1-1c33b0c5932c/bissell_big_green_deep_cleaning_machine_rental.pdfIn PDF document text
    • https://329f26c8-0235-4118-8622-173d264d9cf1.filesusr.com/ugd/221f3a_a48e9a08b4a047ac95da96c22cb8b33f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bupijila/mapezufi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/edbec932-b526-4f31-8f40-62bdcf723442/rivarexemi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5af2dea9-e6df-458a-a22a-82d959fa257b/sophos_endpoint_security_and_control_price.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fabf01c3-31ef-4b54-b7f4-7edd20a38b82/16495281793.pdfIn PDF document text
    • https://0115c081-d8bc-4983-a705-81db93bf1442.filesusr.com/ugd/990402_f0efbf53bf50453da4223bcedfa22213.pdf?index=trueIn PDF document text
    • http://jokosen.atwebpages.com/what_is_the_best_water_cooler_dispenser_to_buy.pdfIn PDF document text
    • http://sutexuvidag.myartsonline.com/zemop.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_off0000f277.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF277 4952 bytes
SHA-256: 596825a540e2d9227e8d80e790d7bde2795ce7e23d66dc15bd5a52765e8d18ad
font_01_sfnt_off00010350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10350 11428 bytes
SHA-256: bcf54996a5c4a734f0db91b87b6e3cd962bf23afd8d3f976187aee868d72e1f4