Malicious PDF — malware analysis report

Static analysis result for SHA-256 83599da6819c078e…

MALICIOUS

PDF

73.5 KB Created: 2021-06-24 05:57:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 54f4d65484e74975c5b14240faf4cbb8 SHA-1: f76e6fbff5abc6c44fd6260bf455478d07b02156 SHA-256: 83599da6819c078e091283848d9e291aba74e6c4f1ae43a1a90afebfd745ed25
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to multiple compromised WordPress sites and disposable hosting domains. These links likely serve as redirects to phishing pages or malware download sites, a common tactic for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/j4oalla7n7h7eu6a080lq49i0q/xutinuva.pdf In PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/7688086834.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1609e4ba67a91b---nuzewafanekipisum.pdfIn PDF document text
    • http://allasclub.com/campannas/file/17590790732.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160724c70056b3---nadukod.pdfIn PDF document text
    • http://payassistinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1c78d7df0---xokubaki.pdfIn PDF document text
    • http://nanoscopy.ru/uploads/files/dosusozujigesezalup.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/991cb78848ea830e79d4a2d9d600287a/riwogoperonakibi.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/617c51f2e21a8c4fe7eb899208892efa/dagefagorabizabibe.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/956f090603d8fc7c936753b9c4f41b4f/5394751370.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081628dabd26---40409792274.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f16bd47a0e---637031767.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/djfeeabbh1tj1gucol8ohjrfa2/kasusekegab.pdfIn PDF document text
    • https://fontaine-eva.fr/userfiles/files/23033373715.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/8081802576.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/it6stg8st7cqc2ekt2531r7ckn/58340678508.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=statistics+without+tears+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE074 5404 bytes
SHA-256: d838189ccc7b2707a493fb647a3708d2778672ac73fe95b693fdc2f906f1496c
font_01_sfnt_off0000f2e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E1 11348 bytes
SHA-256: e12b0ba1cae428f90cecc9d460f8027c11e148e7cdb47db1949548183c855b33