Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f928def1e3e1efb…

MALICIOUS

PDF

91.6 KB Created: 2021-09-06 14:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 322a2da95fec52734a46f7fc4e7ecf3a SHA-1: aee17347fac4edb8e7c2798481d837bf3681720a SHA-256: 4f928def1e3e1efbc93242f03d22dc27ca602d6d90c0716be3747151988101eb
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it contains embedded JavaScript and a link farm pointing to compromised websites. The embedded JavaScript likely serves to redirect the user to malicious external URLs, facilitating phishing or further payload delivery. The presence of numerous links to potentially compromised WordPress upload directories suggests a tactic to host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://eros-arena-reutlingen.de/eros/userfiles/file/97674960372.pdf In PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6afac8e27f---5473708651.pdfIn PDF document text
    • http://maiodi.com/userfiles/files/51284104728.pdfIn PDF document text
    • http://cepsagibyachtfuels.com/images/photos/jamiwaniwi.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d14dd792b8---beluvipugebemesap.pdfIn PDF document text
    • https://jkmart.net/FCKFiles/File/506911033.pdfIn PDF document text
    • https://peterdegendt.be/file/93474212954.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b98ac504e80---gosewosezudomuvuxisilevag.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7b359d4a17---1928230085.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161207ca74713e---41981664727.pdfIn PDF document text
    • http://giovanninociti.com/userfiles/files/fuguketinobaw.pdfIn PDF document text
    • https://skywaytravelandholidays.com/ckfinder/userfiles/files/nofusiwuranosasakudosag.pdfIn PDF document text
    • http://www.ernakulamarchdiocese.org/www/js/ckfinder/userfiles/files/58093835447.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090947214d04---34547863143.pdfIn PDF document text
    • https://netwindowvn.com/uploads/userfiles/file/puzezimekefofebapepaga.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16093feb130bce---8222310384.pdfIn PDF document text
    • https://upaspor.com/resimler/files/divezojesubobadiku.pdfIn PDF document text
    • http://oilandgaswork.com/userfiles/file/91578479678.pdfIn PDF document text
    • http://bibliotekaludwin.pl/img/upload/files/60437269771.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/oqnr1bqccstom1knvh8j6q1hd6/damuxupudesigi.pdfIn PDF document text
    • http://maezawa-jidousha.com/js/upload/files/13075944616.pdfIn PDF document text
    • https://cicadit.ro/UserFiles/file/48051369271.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1606f112fbf879---vijoronepigo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=ph%E1%BA%A7n+m%E1%BB%81m+chia+t%C3%A1ch+file+pdfPDF link annotation
    • https://www.thc.gda.pl/ckfinder/userfiles/files/nowidevotogoporolot.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e734.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE734 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF4B 11072 bytes
SHA-256: e4d5bee4da663487b0a8b5e6474ceb0aaff444d0bab2d18941f1c4c9c0dd0fe7
font_02_sfnt_off000117a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117A7 24492 bytes
SHA-256: 746e0a8ccd11d41f31219156e381b73d3a8d8739b5b53d2b015e2660684812b9
font_03_sfnt_off0001563a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1563A 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc