Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcfb2a6053278b33…

MALICIOUS

PDF

74.5 KB Created: 2021-06-05 21:57:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 0f1be9a70c7c87eca11f301f5565ba02 SHA-1: eeb6bf281e0a4f244540c7dbbded377d6b5d60a7 SHA-256: dcfb2a6053278b33700c9b9bdd4b2691af3486571eff6961bf2c2b59e041a3c8
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://crewmak.ru/pbw?utm_term=using+and+understanding+mathematics+7th+edition+answer+key+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4369632/normal_602f356f2c78e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366042/normal_60bae837cad90.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379046/normal_601bb8330edef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366622/normal_604ce311e77b8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4394082/normal_601b9797efbb8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381081/normal_5fcf23309f493.pdfIn PDF document text
    • https://vanuseru.weebly.com/uploads/1/3/5/3/135350539/rugajasazenifoz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449399/normal_5fe1d3a420091.pdfIn PDF document text
    • https://rojisubul.weebly.com/uploads/1/3/4/5/134593633/f38c204c837f7.pdfIn PDF document text
    • https://vasukoxenubepez.weebly.com/uploads/1/3/4/4/134475355/kuramefiritariwazus.pdfIn PDF document text
    • https://rofaxebawo.weebly.com/uploads/1/3/4/7/134750080/tedes_rulepomukulax_tosej_wivokevifuf.pdfIn PDF document text
    • https://kibujedazem.weebly.com/uploads/1/3/5/3/135347543/deroponiwodos.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/9d1469f3-5bc6-4ed2-9647-55f733279c1f/what_is_my_dads_cousins_kid_to_me.pdfIn PDF document text
    • http://vedufid.pbworks.com/w/file/fetch/144604575/lusubugukijosemewebukom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/69c62105-428a-41c3-aa5c-838a87f23ea9/92772566916.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/60c871c8-407b-4732-8eaa-0db9a5509789/calvin_and_hobbes_first_comic_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b7b24b11-1bbe-4a0a-bc0c-dd2348152cd3/maths_textbook_class_7_maharashtra_board.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14b66212-dd56-4dca-b53d-c2627ad0c562/julian_calendar_vs_gregorian_calendar_converter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b2b987e3-0de7-4e7b-86fe-6fae5a82c740/learn_korean_worksheets.pdfIn PDF document text
    • http://kukepofarit.pbworks.com/f/how_many_numbers_are_in_a_dhl_tracking_number.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a66ebb4f-9cc4-40b5-a5cb-2e7eec07b3c2/pomefijekakitiviwu.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_off0000e2af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2AF 5868 bytes
SHA-256: 7550c13c45a964e4e18ca57df5a040684ed8adb0cf4b2f7545bff65d57c3ee61
font_01_sfnt_off0000f6a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A5 11196 bytes
SHA-256: 71854fb4dcd3453b235bba9e064a6f8d4930311035ea11474cb06a8508009ca0