Malicious PDF — malware analysis report

Static analysis result for SHA-256 1857c5988ef4cb80…

MALICIOUS

PDF

80.7 KB Created: 2021-09-17 10:46:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6fe23a979456762f288d342db8afbe31 SHA-1: 586a11f809316743c9cd313200dc49c867811494 SHA-256: 1857c5988ef4cb8005f5b8ab5e4621e62f4bdb6579a4ee91ce8a1fa4cab121b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • 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.
  • 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://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/8aa9d2561e2b44996d67d7d8ffb32a02/nonezaxu.pdf In PDF document text
    • http://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/26545650961.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143f08023642---61763954629.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/81810738179.pdfIn PDF document text
    • http://vividconcept.in/userfiles/file/katuvelezis.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/virok.pdfIn PDF document text
    • http://innovad-ltd.com/userfiles/file/gatararogufedidukob.pdfIn PDF document text
    • http://hotel-gerard-dalsace.com/upload/document/meguxulime.pdfIn PDF document text
    • https://istanbulbalbir.com/upload/ckfinder/files/5717618037.pdfIn PDF document text
    • http://arkystudio.eu/userfiles/files/24724716721.pdfIn PDF document text
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/kenifujuw.pdfIn PDF document text
    • https://laser123.com/geektic/files/9171654564.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/fekojazapito.pdfIn PDF document text
    • https://e-ceramika.pl/userfiles/file/robarite.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613938e32cae9---99074014389.pdfIn PDF document text
    • http://namkhoabacninh.com/images/files/bagusuzapu.pdfIn PDF document text
    • https://99shayari.in/userfiles/files/24246115260.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/karimuxibikikuvavewa.pdfIn PDF document text
    • https://hinodanang.com/uploads/image/files/87515619174.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/183391679.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/konoxofabogiz.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16141d372ed384---taxipebixelaxugetesik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=laughing+your+way+to+passing+the+pediatric+boards+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_off0000d650.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD650 11248 bytes
SHA-256: 0fb85137b7e92d498cf4cc4302f7f4e5d8662ae14159661e813c8e018672ffb8
font_01_sfnt_off0000f04c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04C 17312 bytes
SHA-256: 43740c0369d4e8af0fc1e43de5d9fb9e616a6f76893ec1cffaea6ea1b2c0d7f6
font_02_sfnt_off00011d31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D31 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1