Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8546df024f56b7b…

MALICIOUS

PDF

79.1 KB Created: 2021-09-14 21:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 570dd64487028bbd7322e850f27b1e10 SHA-1: 141b8d7f227b5341f1f55a4f9cf2ac4af8ab164c SHA-256: c8546df024f56b7bbf2bbaa3635916e156c8a2bc0d243c8c0e0b32525ace5196
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, several of which point to compromised CMS upload directories. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to potentially malicious or SEO-manipulated content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://peptidturkiye.com/ckfinder/userfiles/files/vagugo.pdf In PDF document text
    • https://pachetedeturism.ro/images/files/pamogupipotitowoninijuv.pdfIn PDF document text
    • http://thoitrangvabaoho.com/Images_upload/files/90650215406.pdfIn PDF document text
    • http://zabbeleecooking.com/ckfinder/userfiles/files/lozugusu.pdfIn PDF document text
    • http://mtcnx.com/upload/fckimagesfile/budezavepamajijutaledo.pdfIn PDF document text
    • http://parentini.it/userfiles/files/kurugif.pdfIn PDF document text
    • http://ilsungwarehouse.com/userData/ebizro_board/file/fepuxeda.pdfIn PDF document text
    • http://vistobrasil.net/uploads/file/zekefipisamotidefi.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/f1174b05c5d5d207dcf1f8fbf13666dc/55403642845.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/wazob.pdfIn PDF document text
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/rivekapuwamexakurugagus.pdfIn PDF document text
    • http://baldonimarcostudio.eu/userfiles/files/zasukuxowematowidozamusox.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16134bdf86c82c---kamaropolovuxuj.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/26312845128.pdfIn PDF document text
    • http://www.superior-inkjet.com/login/ckfinder/userfiles/files/69586889948.pdfIn PDF document text
    • http://tamphuhiep.com/Images_upload/files/41668700545.pdfIn PDF document text
    • http://nanopena.cz/upload/file/xafabaxututakures.pdfIn PDF document text
    • https://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/90402757849.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/wuwamimoteni.pdfIn PDF document text
    • https://yoimart.com/upload/file/20210911043334.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/43874214905.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fda04b7932---japerefokinidezisamum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=god+live+wallpapersPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d04e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD04E 18348 bytes
SHA-256: d29a969ec7e49d26db13980efa19ca636cf9b04901c13f4148534891c82953d2
font_01_sfnt_off0000ff6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF6D 10376 bytes
SHA-256: b816b590c4e29eefc14dc07f0b74ea94b91caf09a1e3f58459396a46ba5f2872
font_02_sfnt_off0001170c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1170C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1