Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b8535728d3a8c53…

MALICIOUS

PDF

74.4 KB Created: 2021-06-08 17:55:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 516cce8bd0298e6d731f8ea7fc287f64 SHA-1: 09234998a98bebbf3c0e5b3b8e819b16d93b8a68 SHA-256: 2b8535728d3a8c53da661c2fa2e5f5ee7f94db44a6a7fa60bdd732371d6144a9
96 Risk Score

Malware Insights

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

This PDF document contains numerous links to compromised WordPress sites, acting as a link farm. The ML classifier strongly indicated maliciousness, and the presence of embedded URLs suggests an attempt to redirect users to potentially harmful content. No scripts were extracted, but the overall structure and URL patterns are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://infrive.ru/uplcv?utm_term=g+arpeggio+violin PDF link annotation
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dde2418999---rogogiperefebalirov.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a3e92589a64---62837509145.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/f3283625700ac311d6b89bcfac24e81d/86604682470.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/4588e2c629e1c49bdc4acbed4a034f9e/18139938327.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/eb951cbd1c048cbd6206026045866f21/vaxiwanegumexulepetigu.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1609c85d9c08d2---bevusemawow.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b0122dcfba1---50497225641.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a88e087e56---41060690802.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608a493b402a8---74306939047.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d4b50517a---91469887024.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/69308174690.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608e4d1c783cd---97697971149.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/u8nv6mh2ovu0o3c02cgq08cqvb/wamebarubi.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b572bf5ada9---selas.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/jevesilasalidibaku.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000e5fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FC 4900 bytes
SHA-256: 33d408b00352453089716b1879396418767cc2179aa6fa61e610119db61ac50a
font_01_sfnt_off0000f6c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C5 11360 bytes
SHA-256: b8689671f94752301c029b170b7c6364e73c0a4e7e9b8043f5db40168f6aca50