Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7031dfaab14e2da…

MALICIOUS

PDF

83.0 KB Created: 2021-09-01 13:31:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 695f3a8c0408f4ca900ac206c061001a SHA-1: 90732cccda13fda6e8cf5a70a17ef366158c1e43 SHA-256: a7031dfaab14e2da49fec027aea2a142a3edcc57188ef3dc3c83a8e66b53f957
136 Risk Score

Malware Insights

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

The sample is a PDF document that employs a social-engineering lure to trick the user into installing a browser extension or update. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content. While no scripts were directly extracted, the presence of the 'SE_BROWSER_INSTALL_LURE' heuristic and the nature of the URLs strongly indicate an attempt to deliver a second-stage payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://huntic.ru/uplcv?utm_term=auto+refresh+extension
    • http://delvalle68.com/clients/54584/File/zapumijon.pdf
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/8acfb44f93d50251048ca0ce6206ffc0/gevawejetis.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cfb6bdb4a0b---69592621040.pdf
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077396a8a859---79002729090.pdf
    • http://resumesfromabove.com/userfiles/file/79830637628.pdf
    • https://assignmentmart.com/ckfinder/userfiles/files/75658998213.pdf
    • http://takeacode.eu/user/d41d8cd98f00b204e9800998ecf8427e/file/zidewulozodegob.pdf
    • https://jiu-hang.com/upfiles/editor/files/wugin.pdf
    • http://flirtproducties.nl/ckfinder/userfiles/files/32698005726.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/kqqug2smnldhsgbq4lij88lntm/34454395732.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1611e4258a201a---pafavujowuxugusaso.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16082236f831d4---fexetabefumitinexoxij.pdf
    • https://affordans.com/ckfinder/userfiles/files/76737665510.pdf
    • http://popnmusic.fr/userfiles/file/52293142967.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8559bc0d0---fokizogugirezuvedorone.pdf
    • http://m-camper.ru/ckfinder/userfiles/files/kunegurekuxufimixina.pdf
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/jsqra53ev87trpqafkevbcaddi/6227261703.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/cdb9ce257feb6f51407c893c37dc2925/jikexutuwezejodapuvafofog.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/osor3eqnbrbr3io0lfmunh32p2/saviwefuwodidimupapate.pdf
    • https://yepsell.com/userfiles/files/7623035681.pdf
    • https://daismene.it/file/6704461486.pdf
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c8a9b27dd---bupuravet.pdf
    • http://jplus-ag.com/upload/files/BodyFile__60E6567B17E28.pdf
    • http://amandamaitland.com/images/file/vijuvekamigavemeregu.pdf
    • 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_off0000de17.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE17 16792 bytes
font_01_sfnt_off0000f629.bin
5a6a758635d74ed46c9b493dfd19d10d23287989e82349430771c5518886278f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF629 18356 bytes
font_02_sfnt_off000125a9.bin
beb4c959b2dca948edd303f46dc7f8bf586de6bfd63015d1d1974a2d95a0de8f
pdf-font-stream PDF embedded font (sfnt) at offset 0x125A9 10288 bytes