Malicious PDF — malware analysis report

Static analysis result for SHA-256 281a571500b5a733…

MALICIOUS

PDF

78.2 KB Created: 2021-09-04 16:48:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: d7a4d492092278adbba8fca98c5853ab SHA-1: a7d5406e9906bb70e03506647ae1eff84f6ecf7a SHA-256: 281a571500b5a7339111700c0c0617fcb2f500209d7bf5b840826a60ad1a6e05
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories and disposable hosting domains. The ML classifier strongly indicates malicious intent, and the structure suggests a link farm designed to lure users to external sites. No scripts were extracted, but the overall pattern is consistent with a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160804b7058ac4---9604775186.pdf In PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c033f5f3c33---37978258358.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/10773605312.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/79807715613.pdfIn PDF document text
    • https://faltprasten12.se/anvandarbilder/70/files/55990545567.pdfIn PDF document text
    • https://brickzoo.it/file/15005317125.pdfIn PDF document text
    • https://aristi-trap.com/upload/users/files/11411151870.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/gigurirawaxubaserixinuvit.pdfIn PDF document text
    • https://defaico.com/d/files/voniwofe.pdfIn PDF document text
    • http://appli-veolia.net/ckfinder/userfiles/files/sumixisin.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/58785891307.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/gugawoludo.pdfIn PDF document text
    • http://toonesk.com/upload/juman.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/kaleratuka.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/pisaxo.pdfIn PDF document text
    • http://holzbau-napetschnig.at/67228900028.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/0a9681894fdb5d9f5aede9eb9fa902e3/4134511394.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/direzazewo.pdfIn PDF document text
    • https://puppometalli.eu/file/femosojoxulejapam.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/20813610789.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160842392ed30e---823609750.pdfIn PDF document text
    • http://strandedtattoo.com/file/fefiwupoxavebarumado.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/rimoj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=shure+svx24+pg58+specs+pdfPDF 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_off0000c59a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC59A 11160 bytes
SHA-256: ddba67ad57d21497dcae287f1541e9b095c6bd7348e2433e6e40f536a632ac74
font_01_sfnt_off0000dfc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC1 19360 bytes
SHA-256: 6511099c4b62161cf339b411426e10119754f74e614758ffe51cb8deb240bae9
font_02_sfnt_off00011371.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11371 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1