Malicious PDF — malware analysis report

Static analysis result for SHA-256 2e9b18398ced0acd…

MALICIOUS

PDF

74.0 KB Created: 2021-03-30 16:56:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2ff9239ee6146713a313c6e9dbc43392 SHA-1: 9cc69acbdf427b9326027ecf28f3aa82285c9648 SHA-256: 2e9b18398ced0acd1cb1748899c0e0aefedd65de63cf15a9bd03dcb93bacab87
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with one heuristic specifically identifying a 'PDF_SEO_LINK_FARM' containing 30 external PDF links. The primary URL, 'https://jacksth.ru/wix?keyword=compound+complex+sentences+worksheet+pdf+with+answers', appears to be a lure for search engine optimization. ClamAV detected the file as 'Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0', indicating a phishing or trojanized PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jacksth.ru/wix?keyword=compound+complex+sentences+worksheet+pdf+with+answers
    • https://cdn.sqhk.co/letarezetap/qCFbfIF/free_funeral_program_brochure_psd_template.pdf
    • https://cdn.sqhk.co/difanemifal/hbiC1gg/infection_causes_mouth.pdf
    • http://faxozulakevosos.iblogger.org/burnham_on_crouch_primary_school_ofsted_report.pdf
    • https://cdn.sqhk.co/xovatapegil/XNP8Lw5/bouncy_castle_fips.pdf
    • https://cdn.sqhk.co/wisaputal/JIicjhi/printer_3d_model_obj_free.pdf
    • https://cdn.sqhk.co/kanereneb/gj0ifc8/3361562396.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/sumesawoxajew/the_best_ice_cream_makers_for_sale.pdf
    • https://s3.amazonaws.com/xepululejiwof/employment_standards_act_worksheet.pdf
    • https://uploads.strikinglycdn.com/files/1a8dc52d-1289-4147-a5cb-125e531624e0/can_you_use_a_bundt_pan_for_any_cake.pdf
    • https://4900ecec-7ac1-411c-be2c-b077674085c8.filesusr.com/ugd/493135_9ea3733aec7c431f9c6ed17347b0cf32.pdf?index=true
    • https://s3.amazonaws.com/zafijukopa/verevefoduzusamufurog.pdf
    • https://636e06b3-920c-4898-b827-ef778bbbc101.filesusr.com/ugd/40512e_906f6d79c050426da322435579b7ba32.pdf?index=true
    • https://7d6e376e-1ee3-4df5-88c1-8d1511d419f8.filesusr.com/ugd/7dd30d_858f71f5cb6c4c8b88a81385e91cd530.pdf?index=true
    • https://s3.amazonaws.com/jovekus/fojerufanufawikuj.pdf
    • http://ripofosefalub.rf.gd/annual_report_design.pdf
    • https://uploads.strikinglycdn.com/files/2093d398-95a4-4a59-8f51-8b86954c9751/xugib.pdf
    • https://eee7329a-c4d5-4508-a8fd-a8ba515f7d9f.filesusr.com/ugd/5ed802_394bdd7cbe234c049329b914654e95e5.pdf?index=true
    • https://uploads.strikinglycdn.com/files/b8fcca9c-6196-42a0-8fb5-0d8f1168fc9d/pejananevefodovupotixuvej.pdf
    • https://s3.amazonaws.com/remuv/lowemurub.pdf
    • https://s3.amazonaws.com/fejenijovekozu/how_to_build_defence_platform_stellaris.pdf
    • https://s3.amazonaws.com/muvevanepen/35024400561.pdf
    • https://ff9dba89-6132-4485-99c2-ace8a2453124.filesusr.com/ugd/c3f59f_57e83bf8224040afa5e6c5e5c19146f3.pdf?index=true
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e380.bin
0462547c81ba90b0055e163771613d8b6ff3601915dded58032b733521b33f22
pdf-font-stream PDF embedded font (sfnt) at offset 0xE380 5524 bytes
font_01_sfnt_off0000f62f.bin
8712fbbb16911d59cddf884173b34337a5473e41ef2e14c54504edfb23f77d60
pdf-font-stream PDF embedded font (sfnt) at offset 0xF62F 10608 bytes