Malicious PDF — malware analysis report

Static analysis result for SHA-256 88f43667ddd6f244…

MALICIOUS

PDF

70.4 KB Created: 2021-09-26 07:46:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c8a6dfa2cdc0feca1b5797793f9d7b87 SHA-1: 363369e1c4e8fc1c21738c9ecd7500a0d3d7a324 SHA-256: 88f43667ddd6f24448ec601e45a6aa2df321e24f5cd0e2db39a94412ca5dde8c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged by heuristics as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://corpus.bg/files/fck/file/jexeximejokejukonixo.pdf In PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d609b49f4e---56996500011.pdfIn PDF document text
    • http://sbstroy53.ru/img/files/2721193327.pdfIn PDF document text
    • http://deborahmayerlawoffices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/volugonapoj.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/16479273794.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/pefopekiwebodigukuditunis.pdfIn PDF document text
    • http://rujiahk.com/uploadfiles/file/lakotenexerajuvozokomiw.pdfIn PDF document text
    • http://opusincertum.it/userfiles/files/metapepuduwu.pdfIn PDF document text
    • http://gr-chem.com/upload/files/zarekonasikerez.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/90189807301.pdfIn PDF document text
    • http://theflowermaker.com/uploads/File/naxiburujilir.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/54312918893.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80360421963.pdfIn PDF document text
    • http://rent2day.ca/ci2/userfiles/files/84224827253.pdfIn PDF document text
    • http://ourconn.com/userfiles/file/202109121504251721.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134cca65811a---13146894848.pdfIn PDF document text
    • http://kancelaria-perfect.pl/app/webroot/media/files/porume.pdfIn PDF document text
    • https://2ruoteexpo.it/ckfinder/userfiles/files/6638003481.pdfIn PDF document text
    • http://munnartourism.com/uploads/file/dutaxiwefufivos.pdfIn PDF document text
    • https://hongming-eco.com/userfiles/file/90568174143.pdfIn PDF document text
    • http://labonscafe.com/userfiles/32679169559.pdfIn PDF document text
    • https://foodsafebox.com/ckfinder/userfiles/files/jokirefazilofamug.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/78333326784.pdfIn PDF document text
    • https://www.pirkitpadangas.lt/ckfinder/userfiles/files/7113610217.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=como+resetar+galaxy+yPDF 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_off0000b106.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB106 10504 bytes
SHA-256: 33f8a1f48855af4d76213c86a18a6e2a6a0a4c19dc1021c1d845fa0065650d82
font_01_sfnt_off0000c912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC912 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e124.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE124 16808 bytes
SHA-256: 60d8b988888c0094c961f1b3fba5137374c70f41f39dd37867244c569b485d52