Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecf8ebc00f0a2f58…

MALICIOUS

PDF

81.5 KB Created: 2021-04-02 18:05:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 17641b715645551398a7a8aebe0a35f4 SHA-1: 55336efee1ac23e33b9d60d6320b56446241f20b SHA-256: ecf8ebc00f0a2f58b45b3e1a5d4af6b5324308548bad810de59c186a4092e9d9
134 Risk Score

Malware Insights

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

This PDF is identified as malicious by an ML classifier and contains a large number of external links, many hosted on disposable domains, suggesting a link farm for SEO manipulation or malware distribution. The document body, though heavily obfuscated, contains metadata related to 'chemistry form 1 notes pdf free download' and the authoring application 'wkhtmltopdf', indicating a lure to disguise the malicious intent. The presence of numerous external URLs, including those on domains like 'bologen.ru' and 'cdn.sqhk.co', points towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • 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.
  • 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://bologen.ru/award?keyword=chemistry+form+1+notes+pdf+free+download PDF link annotation
    • https://cdn.sqhk.co/sogefuluf/qhbR5gi/nuduremugabizi.pdfIn PDF document text
    • https://rogusavonovupe.weebly.com/uploads/1/3/3/9/133997589/mafulirubesoribox.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420431/normal_5fcb47e9774d0.pdfIn PDF document text
    • https://cdn.sqhk.co/sobexofap/FhiQjcx/xawarusuranova.pdfIn PDF document text
    • https://suzitarux.weebly.com/uploads/1/3/4/6/134683800/1369444.pdfIn PDF document text
    • https://cdn.sqhk.co/bosareke/oBYAggQ/xoloritomavatewuperi.pdfIn PDF document text
    • https://cdn.sqhk.co/mekurapiw/6hajgJY/zaduwuseze.pdfIn PDF document text
    • https://cdn.sqhk.co/nisisepolo/Shhnf8d/new_bright_rc_buggy_vortex.pdfIn PDF document text
    • http://mamafiposorugul.sportsontheweb.net/94700102258.pdfIn PDF document text
    • https://cdn.sqhk.co/kinemefuwa/iL6mD4r/celebrated_jumping_frog_plot_summary.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424341/normal_601d8c22552be.pdfIn PDF document text
    • https://vapevaka.weebly.com/uploads/1/3/1/4/131407737/5643142.pdfIn PDF document text
    • https://rugibabolunape.weebly.com/uploads/1/3/1/4/131454120/363a6c7b23.pdfIn PDF document text
    • https://cdn.sqhk.co/gugipusedi/jqvkgdE/hysterectomy_procedure_steps.pdfIn PDF document text
    • https://cdn.sqhk.co/xejudawadoni/gsKmhiv/one_golden_thread.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462036/normal_600b9a793340a.pdfIn PDF document text
    • https://cdn.sqhk.co/mojerakikav/yGjhO5T/jurassic_craft_map_mcpe.pdfIn PDF document text
    • http://fivadoguna.medianewsonline.com/78502465846.pdfIn PDF document text
    • https://cdn.sqhk.co/betewulo/6Yxaz2Q/76439112895.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://944bcc21-9f45-42c2-9889-8cf837fa5d1c.filesusr.com/ugd/50f869_461e1bb1d38f42f88651ce6694928b7b.pdf?index=trueIn PDF document text
    • https://f3ea461b-95fd-44cf-949c-5afda193840f.filesusr.com/ugd/a48928_91a894af2dce4a35ac8414d9e4b19f7a.pdf?index=trueIn PDF document text
    • https://b1e6e3cd-24a2-426a-8b7d-e8f4bd81915b.filesusr.com/ugd/83e584_911c50f2cfb643e882d85ecfa6eaf206.pdf?index=trueIn PDF document text
    • http://gumusimigogasuz.onlinewebshop.net/34219044496.pdfIn PDF document text
    • https://1ac5d900-0c69-4f12-8b1d-4e209472b8d2.filesusr.com/ugd/828753_151912f6d3794721854e2a62686f36b0.pdf?index=trueIn PDF document text
    • https://f405dec1-7f90-4f4c-a861-5286f67d0127.filesusr.com/ugd/ab922d_716e7c0d72ff41f7bc9159b51d7c0476.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_off00010238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10238 5432 bytes
SHA-256: 397dce17a6582e999036be5215e166c5648d0bf11f87c759a53137b6d450b613
font_01_sfnt_off000114a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114A0 10584 bytes
SHA-256: dcea3bf51a280efd024cab8e48b2ad899f9852d2ace4bb0017a11f6229f8514c

Open this report in the interactive analyzer, or submit your own file for analysis.