Malicious PDF — malware analysis report

Static analysis result for SHA-256 53c3677fe7c73e00…

MALICIOUS

PDF

81.9 KB Created: 2021-03-11 03:36:30 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: ef831520dbb53149649ff532ee43e2ed SHA-1: 74e94a09067e841a472667685cf85b281e4c7ae1 SHA-256: 53c3677fe7c73e001dc2ed4ea8facb853daa063b470c88aa9f308f6d4f836698
74 Risk Score

Malware Insights

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

The PDF file contains multiple embedded URLs, with one specifically pointing to a suspicious domain ('vilenefex.ru') and containing a 'utm_term' parameter suggesting a tracking or phishing context. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates the PDF is part of a link farm on disposable hosting, further supporting a malicious intent. The ML classifier strongly flagged this PDF as malicious, indicating a high probability of malicious content or exploit.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=hp+deskjet+3050a+j611+check+ink+levels PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4490265/normal_5fcb1a5ed8baf.pdfIn PDF document text
    • http://alphabitx.com/how_to_change_my_calculator_to_radians97gy7.pdfIn PDF document text
    • http://vykupavto54.ru/wufujeletohy8s6.pdfIn PDF document text
    • http://ladekepevij.mygamesonline.org/andrew_loomis_espaol_dibujo_de_cabeza_y_manos.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476429/normal_5ff929aedfb94.pdfIn PDF document text
    • http://sevagawos.getenjoyment.net/how_to_install_elgato_hd60.pdfIn PDF document text
    • https://fixexetakofipu.weebly.com/uploads/1/3/3/9/133997797/gapoxololab_zunaperoz_jerefolifubos_xufujositepil.pdfIn PDF document text
    • http://miwasigal.mywebcommunity.org/45754456602.pdfIn PDF document text
    • https://favipipuwebex.weebly.com/uploads/1/3/5/3/135397367/nuzutelufajupe-jizorimof.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382209/normal_5ff4976e28146.pdfIn PDF document text
    • http://form-lnstagramcopyrightservice.com/bafg_formblatt_3_wie_ausfllenj7rv6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365652/normal_604946c35850d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456114/normal_601d8e74cdbbd.pdfIn PDF document text
    • http://suziterunedoloj.sportsontheweb.net/problemas_sobre_angulos_de_elevacion_y_depresion.pdfIn PDF document text
    • http://supernefritroller.xyz/77899669025oqdka.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/d3d716df-4499-4ec3-8d1e-00dcb1a4e521/onkyo_tx-nr616_setup.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d6e2335c-2658-428e-9cef-b5d0cd39caea/linux_mint_best_development_environment.pdfIn PDF document text
    • https://ba10d46a-d7c1-43af-8542-f1a50f31aa8a.filesusr.com/ugd/4dded2_8d2b9d8db1b0495dbcfdc364abb47fce.pdf?index=trueIn PDF document text
    • https://9a60fab3-6fb0-4be7-9305-b2e3cc44d963.filesusr.com/ugd/811c4f_61be49aef1bb4ae7938524b36c3c8c24.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/200af1cb-f0fd-473d-9811-ed19ee649972/33955560589.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bed1ff7e-4b96-4407-8516-7709807f992c/wexiwivusorubutoxo.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_off0000fed0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFED0 5860 bytes
SHA-256: 7af5b4078a1f41adfda38ea16706d5baf0d612c491106c2d92a2d40046945acb
font_01_sfnt_off000112d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112D7 11656 bytes
SHA-256: bf68068e1cc95c93521c31b454b1e6ca2e1e63c9d72a763a8dcb00f0f565fd11