Malicious PDF — malware analysis report

Static analysis result for SHA-256 886538c60754c1de…

MALICIOUS

PDF

69.7 KB Created: 2021-10-02 22:14:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f90a5600c91bdcb22090cc0b148f7d59 SHA-1: be97c09ec4f380c3811e8ec95dcba397843f0b16 SHA-256: 886538c60754c1de4fb02746f452879ea7dd331c44b13bde56a6aa60992e1677
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous embedded URLs pointing to various domains, many of which appear to be part of a link farm. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically identifies this pattern, suggesting the document's purpose is to redirect users to potentially malicious sites. No scripts were extracted, and the document body was unreadable, limiting further analysis of the exact lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://olivierdaulte.com/ckfinder/userfiles/files/wodifadedobimagowesaf.pdf In PDF document text
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/nudibatewuvegofiburiw.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/vazazabirolevepaw.pdfIn PDF document text
    • http://www.lircai.com/web/inline/file/segigutizetomez.pdfIn PDF document text
    • http://thueotodn.com/uploads/image/files/zofokazig.pdfIn PDF document text
    • http://retrievers.su/ckfinder/userfiles/files/85086916934.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/wuzebogusomebawozolesi.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/guvigazasizoxifoginaw.pdfIn PDF document text
    • http://blankheich.de/images/uploads/file/nagisesopotolavexodixofuf.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/1236117792.pdfIn PDF document text
    • http://beerskiboot.de/img/upload/file/61963902154.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/vazepenuxuge.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/jufuvaxofig.pdfIn PDF document text
    • http://ecilingirler.com/resimler/files/28028962050.pdfIn PDF document text
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/8384888638.pdfIn PDF document text
    • http://kite-surf.sk/files/tidoxuradilinad.pdfIn PDF document text
    • http://7serve.org/userfiles/file/20210928004545.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/29431232142.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/zedoji.pdfIn PDF document text
    • http://miyisz.com/mingyi/images/userfiles/file/rowux.pdfIn PDF document text
    • http://fotografieindex.nl/images/uploads/69910640760.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/21168483260.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=exponential+vs+linearPDF link annotation
    • http://perfecturology.cafe24.com/upload/editor/imagefile/89997917436.pdfIn 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://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_off0000b0b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0B0 16124 bytes
SHA-256: 5d18babe3705e6ac81d7292d8e38764f47051e80892b280237bb0ede42d5bf00
font_01_sfnt_off0000d98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD98B 10396 bytes
SHA-256: 5bcc7e1b257ce5a03b7f037709142975da4a3fbf83f3add109c43fe1fee57b68
font_02_sfnt_off0000f13a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF13A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1