Malicious PDF — malware analysis report

Static analysis result for SHA-256 a776bd651ccc15fe…

MALICIOUS

PDF

79.5 KB Created: 2021-04-07 20:07:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: e25124d60b46f25433a98f15cec76fa2 SHA-1: eb17fe7f751b4530b4c552a899d3cb49affd0835 SHA-256: a776bd651ccc15feb3edcc15558e4a86c7a082ebd6f536e41ca44e9feb922468
126 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to other PDF files hosted on potentially disposable domains. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.
  • 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://resalured.ru/wix?keyword=administracion+robbins+coulter+12th+edition+pdf PDF link annotation
    • http://bigpleasure.ru/darekidubadorotaxama8vlbm.pdfIn PDF document text
    • https://cdn.sqhk.co/xudadidi/hgddjhh/tennessee_titans_roster_2015.pdfIn PDF document text
    • http://mosdendy.store/cheluvina_chittara_songs_songsb3fjm.pdfIn PDF document text
    • http://jushq.club/71752148899nsra7.pdfIn PDF document text
    • https://cdn.sqhk.co/fekigimuzib/hfggGHm/pivebedupixudove.pdfIn PDF document text
    • https://cdn.sqhk.co/vilubofi/ihjxmoj/16080550896.pdfIn PDF document text
    • http://wwwbcpzonasegura-viabcp.com/58126224608o8mfx.pdfIn PDF document text
    • https://cdn.sqhk.co/jogekiluse/ghcQ5ia/commuter_rail_boston_landing_to_back_bay.pdfIn PDF document text
    • http://healingtunes.ru/bugizijawubeganitusi0j4lu.pdfIn PDF document text
    • http://info-pages.ru/elinchrom_d-lite_rx_4_4_to_go3z41r.pdfIn PDF document text
    • https://cdn.sqhk.co/vedukosamo/XjcWji8/easy_diy_face_mask_youtube.pdfIn PDF document text
    • http://mesretly.xyz/64199863164nruy9.pdfIn PDF document text
    • http://afracheat8.xyz/22550740876pv4my.pdfIn PDF document text
    • http://online-bestshop.xyz/zoom_5352_router_firmware_updatekua4w.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://7c5e2310-e79b-429e-9f4a-70471a43dcce.filesusr.com/ugd/8ec1ef_717f8bd3ebae463d9bdf792bf2902854.pdf?index=trueIn PDF document text
    • https://1ba6f066-89d4-4445-b8a9-08a6de046ef2.filesusr.com/ugd/d40554_ae6a9d6729014a3d90e9425346225c05.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/57ce0331-75d2-41fe-b73a-95969f72b43a/dell_optiplex_755_sound_drivers_for_windows_xp.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d794d53-c353-488a-9225-9ea800ca3901/21345418615.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e450cb94-dcd2-446e-aa8f-2016bdc755d9/nombre_de_los_grupos_o_familias_de_la_tabla_periodica.pdfIn PDF document text
    • https://6f8cb219-4830-455d-9ced-b55e65700e85.filesusr.com/ugd/fd30ac_dc8492c874bc45feb868a1374d364fea.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f8d2b5d-8684-47a6-b9bc-83619f0d39ec/racing_ruined_my_life_lyrics.pdfIn PDF document text
    • https://bf130ee1-1463-4c69-9604-1b23772ced92.filesusr.com/ugd/b4609a_be8fa6a8e2524747b66a7fb0d1d4b184.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF940 5708 bytes
SHA-256: 05f30d6ef8f51bdd783122dfb4de1487400bd6c05a1ae8ad4adc1b0f1a228ab4
font_01_sfnt_off00010c80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C80 10516 bytes
SHA-256: d9a69556002df40a0c55b145bf8b3393d183a8998e8470166ad999aa38501f5c