Malicious PDF — malware analysis report

Static analysis result for SHA-256 915afa3e7a4f429e…

MALICIOUS

PDF

83.4 KB Created: 2021-09-24 02:26:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8419f336328965cbd5d1be4e6dc9c26a SHA-1: ae22cd1eb4ba9360ad6ce8f9e2b7c33a67f1304a SHA-256: 915afa3e7a4f429ec3e2df3dd8bb8897e0c9dcb636b8a8de5ba98cb1ce76c48b
136 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to various PDF files hosted on potentially compromised websites, a common technique for distributing malware. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document likely prompts the user to install a browser extension or update, which is a social-engineering tactic to facilitate further compromise. While no scripts were directly extracted, the nature of the link farm and the lure suggest the PDF is designed to lead the user to a malicious download or exploit. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://sys-svinding.dk/userfiles/file/57927064277.pdf
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/leroguv.pdf
    • https://avflash.nl/upload/files/fidivosezejafunoxowaraxox.pdf
    • http://www.ciesol.com/ckfinder/userfiles/files/58138062850.pdf
    • https://duragloss.pl/userfiles/file/28773977237.pdf
    • http://osoboebludo.com/ckfinder/userfiles/files/berime.pdf
    • http://ty-universe.com/image/files/20210901_150556.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea13c1a6d2---2463524791.pdf
    • http://epplast.com/files/file/12898213209.pdf
    • http://nemeckystrakac.sk/editor_uploads/files/lumigife.pdf
    • http://iwort.de/userfiles/file/91619709749.pdf
    • http://corporatiegids.nl/uploads/files/40431678974.pdf
    • http://stardentalcare.org/userfiles/file/80229564055.pdf
    • http://hatowo.com/app/webroot/uploads/files/20064333148.pdf
    • https://expobar.vn/app/webroot/files/images/pages/files/gefarov.pdf
    • http://dsacare.com/admin/uploads/file/lijut.pdf
    • http://foto-recepty.sk/images/fotky/zosajimelaje.pdf
    • https://rgcsmt.org/ckfinder/userfiles/files/renewegumuriz.pdf
    • https://iwistw.com/upload/files/99307413058.pdf
    • https://philly.drinkpoint.com/uploads/files/jijonovukazapinugibup.pdf
    • https://smwebtechnology.com/arishayurveda.com/userfiles/file/bukipufomaxo.pdf
    • http://willbramephotography.com/55750334730.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/5fmslniqnfrpmo2nvdsr6qc42r/fukivaxewateroxepunuwajef.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16142afc352d93---vizavekanu.pdf
    • http://tomekorea.com/userData/board/file/muladidejebitut.pdf
    • http://www.vegagastro.pl/upload/file/40872403707.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+factory+reset+moto+e4+plus
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df4d.bin
714c1bb86115105481d0caf2d91317b9a707cc3d9dc6329cee487fd89ad9654a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4D 10816 bytes
font_01_sfnt_off0000f872.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF872 16792 bytes
font_02_sfnt_off00011084.bin
0c57221c21d76641bd31fb4666840b1c71e5fc523a8021213498b633e764f816
pdf-font-stream PDF embedded font (sfnt) at offset 0x11084 18160 bytes