Malicious PDF — malware analysis report

Static analysis result for SHA-256 f947a740451c171f…

MALICIOUS

PDF

80.2 KB Created: 2021-05-08 12:53:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 51f605211e72b4d1b5f1840034833392 SHA-1: ee20193754d9e21afc5afd78d074620875d0be3c SHA-256: f947a740451c171f7ddd3f898f339264112ee1979b3cf9f4ab262b3c34fe50f2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF document contains a lure related to a book chapter summary, which is a common tactic for phishing or malware delivery. It embeds a URL pointing to a suspicious domain, vilenefex.ru, which is likely used to host or redirect to a malicious payload. The presence of ML and ClamAV detections, along with the PDF_SEO_DISPOSABLE_LINK_FARM heuristic, strongly indicates malicious intent, likely involving the exploitation of a PDF vulnerability to execute a secondary stage.

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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=turn+the+ship+around+chapter+7+summary PDF link annotation
    • http://nibodilakiwote.22web.org/numuwodaludolividukezufim.pdfIn PDF document text
    • https://s3.amazonawIn macro / runtime command snippet
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/7802c7e2-932a-46ec-81b9-fbd7ca8852d1/cmos_digital_integrated_circuits_analysis__design_4th_edition_solution_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/jigezilor/povaludonejitasalum.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5880b024-ab7c-4110-bd96-7e15ae2b6027/my_side_of_the_mountain_part_18.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5eb5a6d0-47d7-4c07-863b-6892315829b9/windows_powershell_or_windows_powershell_ise.pdfIn PDF document text
    • https://s3.amazonaws.com/zikeko/vesokamidevu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/11cd4487-c5b5-4b79-a05a-d14d7db98b71/cessna_210_maintenance_cost.pdfIn macro / runtime command snippet
    • http://siloxatomikuje.rf.gd/22620690691.pdfIn PDF document text
    • https://s3.amazonaws.com/xuzakob/is_cyberpunk_2077_worth_it_on_ps4_pro.pdfIn PDF document text
    • http://tuzivapevof.epizy.com/sentinel_2_data.pdfIn PDF document text
    • http://gogewarixisude.epizy.com/xonegapesafoxasabomope.pdfIn PDF document text
    • https://s3.amazonaws.com/napejaxosinages/36503332332.pdfIn PDF document text
    • http://vanazabeso.epizy.com/27524920156.pdfIn PDF document text
    • http://gojejamajutemus.epizy.com/client_management_interview_questions_and_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2885016c-c0ff-4b10-9fae-769befb1bdf0/how_to_play_tabletop_rpg_online.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3ccde8e9-8472-4b19-8ba0-4db826887e9a/dovunodujexomiwuwabal.pdfIn PDF document text
    • https://s3.amazonaws.com/ganubifirigevi/17901314082.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d8a1505d-d375-4e6d-9cbc-d66fc999ece4/wajujep.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c38b1085-37fe-4b1c-909c-b4604c1cf49f/muscle_after_40_free.pdfIn PDF document text
    • https://s3.amazonaws.com/tobito/dunkin_donuts_ham_egg_and_cheese_sandwich_nutrition.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57ad99e7-e851-4f07-b538-01bc64154780/freelance_writing_jobs_online_uk.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_off0000fa34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA34 5412 bytes
SHA-256: d11691e9085e8809d6868355bfe600c3e7d3257bed19db79ab856e777cd12a30
font_01_sfnt_off00010c7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C7F 11048 bytes
SHA-256: e00bc217a9306be50830d226cb65127e48fe1686395ff9f596ab5aaa782b7388