Malicious PDF — malware analysis report

Static analysis result for SHA-256 5305283d373a35d7…

MALICIOUS

PDF

98.1 KB Created: 2021-04-11 01:49:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 441dc97f7f2b2a4d6b61d85207e45a82 SHA-1: 76433a48e76cb3c60f4a8feabccf66a708d57267 SHA-256: 5305283d373a35d727337f52c80d3dba4f9275447ace326de0430d194b44eaff
186 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The document body, though heavily obfuscated, appears to reference a 'prep book', which is likely a lure to encourage clicks on the embedded malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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://bologen.ru/strik?utm_term=ap+language+and+composition+prep+book PDF link annotation
    • https://cdn.sqhk.co/silakozafi/iaMCPHF/xatibigavibepinivisufuxo.pdfIn PDF document text
    • https://cdn.sqhk.co/letarezetap/CvgiczF/ragaduwojak.pdfIn PDF document text
    • https://cdn.sqhk.co/titabofasika/asajhLG/salary_for_customer_service_representative.pdfIn PDF document text
    • https://cdn.sqhk.co/migazajigum/jjMgigf/emerging_areas_of_law_uk.pdfIn PDF document text
    • http://safagiko.iblogger.org/centripetal_acceleration_in_vector_form.pdfIn PDF document text
    • https://cdn.sqhk.co/xesofosirija/hdFwibV/books_like_the_girl_in_the_window.pdfIn PDF document text
    • https://cdn.sqhk.co/bowazeduz/ghfhcpe/ufc_fight_tonight_time_ppv.pdfIn PDF document text
    • https://cdn.sqhk.co/xotolodi/Jjg1yjd/gem_defense_chance.pdfIn PDF document text
    • https://cdn.sqhk.co/vulovosovem/hghesht/myradar_weather_radar_for_pc.pdfIn PDF document text
    • https://cdn.sqhk.co/tatidukigag/dZXMhhF/verizon_mdm_help.pdfIn PDF document text
    • https://cdn.sqhk.co/nesorosuxim/Ljfpkib/89683781495.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://010f2e21-25ca-4560-806d-08cbbb7c7db1.filesusr.com/ugd/74a852_eb90e3b4d2d14d7899567c5c675dbf8b.pdf?index=trueIn PDF document text
    • http://majilutiwuxas.rf.gd/synonyms_worksheet_for_grade_1.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b35ca87a-e38a-4344-a18e-588f7a55e1a4/what_order_should_i_read_noughts_and_crosses.pdfIn PDF document text
    • https://dbb1fad9-9c05-458f-9e32-bc0b7f65d7ec.filesusr.com/ugd/451461_33c4027692004906ac00dbd50f09ff3a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kubafezin/lomejagobola.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/19bb8cc1-e9d2-4725-8c29-ec8af769aa5a/pojitixagolira.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b8d5623-8f0c-4b6e-9e11-4aab0780c016/19415482431.pdfIn PDF document text
    • https://s3.amazonaws.com/resabomibogodaw/how_to_pair_plantronics_voyager_pro.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bf56fd34-b82e-410b-8ebc-82fbeaee5915/7850607564.pdfIn PDF document text
    • http://tudaditupuji.epizy.com/53964996786.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13472 5468 bytes
SHA-256: d3be02ab08311291d3297005bb9467b5bd9a2535acfd2c5431ec4bdd8f10749b
font_01_sfnt_off000146e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146E7 11160 bytes
SHA-256: aa613c2e0ff7094f16cb0a4cb11e2c7f4c6f740fb233c75bf782e41bbbf1e08d
font_02_sfnt_off00016c99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C99 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34