Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d137b4f381d1cd5…

MALICIOUS

PDF

79.6 KB Created: 2021-03-21 04:19:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: cbbfe75f5204c2dbcedea65da27c087d SHA-1: b62d00dd734fa4e8395ac0e3f116c9546d750255 SHA-256: 4d137b4f381d1cd535140ea1794ac0c52ebc1de6a440190944a894f2d1d5f44e
166 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics indicate the document uses a social-engineering lure to prompt the user to install a browser extension or update, a common method for malware delivery. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it is designed to lead the user to malicious content or downloads.

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://golowaki.ru/award?keyword=2020+monthly+calendar+pdf+free+download PDF link annotation
    • https://cdn.sqhk.co/genizataxom/ToDuEha/computer_game_company_idle_clicker.pdfIn PDF document text
    • https://bofazereb.weebly.com/uploads/1/3/4/6/134675062/16e6f3d97a532e0.pdfIn PDF document text
    • http://repair-telefonov.ru/sozuvukobiximuwatipcerbn.pdfIn PDF document text
    • http://confirmyourverifiedbadge.com/diet_assistant_jobs_near_mep250q.pdfIn PDF document text
    • https://cdn.sqhk.co/nikofejujel/gjfgijd/33262622464.pdfIn PDF document text
    • http://cashbackmoney.info/curious_george_book_author48qcd.pdfIn PDF document text
    • https://tiwabegi.weebly.com/uploads/1/3/0/8/130874513/ffc827098399d.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://uploads.strikinglycdn.com/files/8106a104-85fe-407c-817f-b7edaf543bd0/tabla_de_verbos_en_ingles_en_pasado_simple_y_participio.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9e8a140-3777-42f6-8f5b-a1b9c4509c1e/jifival.pdfIn PDF document text
    • https://s3.amazonaws.com/bisegilupuf/pazabelulib.pdfIn PDF document text
    • https://170a7d3c-74f0-42f5-9ead-98ae292a4922.filesusr.com/ugd/a18aa6_14ea88bfedfe4bbebfd702fa627bcfb3.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/norozovijalu/how_much_does_a_tracfone_sim_card_cost.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/761d99df-b5c0-4a2d-a999-f6eac528ef82/modern_operations_management_theories.pdfIn PDF document text
    • https://s3.amazonaws.com/xasovewipeje/85606869016.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/645bf5e7-12d9-4044-b542-a09879a370fd/sagapebuv.pdfIn PDF document text
    • https://720c7b34-a033-4bf0-83ea-6be17de98aa2.filesusr.com/ugd/03ef8e_0d0cee5d127e4572ad4d4a930959ff2b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fejakixoweka/does_the_dyson_v10_have_a_reset_button.pdfIn PDF document text
    • https://6196a4e6-b3b5-4a85-a139-4ec84e0a53d9.filesusr.com/ugd/d01287_0375d12f936a4fc5b6ca1b17b302c2d7.pdf?index=trueIn 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_off0000ec98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC98 5328 bytes
SHA-256: c99e00be11ae71c5118df1bf4b398ea4037d139f4752b08700bd6c83a9547449
font_01_sfnt_off0000fe89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE89 10512 bytes
SHA-256: e4f6e5d95b9950f705602e2eb885adbf76aeef3d8673e9255044b049e72084bb
font_02_sfnt_off00012293.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12293 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c