Malicious PDF — malware analysis report

Static analysis result for SHA-256 8551dcb91bafe6bb…

MALICIOUS

PDF

71.0 KB Created: 2021-04-30 18:47:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: c72baf96d184bb2c53a62a4327c8a462 SHA-1: 2a65fba252c59a1d2ed8c56e61f28b3296a61c2b SHA-256: 8551dcb91bafe6bb96ae4cf452bb80896dbfb9b01ff51d485fe8aaac2812181b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious Link

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The embedded URLs suggest an attempt to redirect users to potentially malicious content, aligning with phishing or malware distribution tactics.

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://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/77e87efc2404615cf9cc1de068da9f86/35964745805.pdf In PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/83063063358.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607fef90c81b8---43298945910.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073857e8cd03---rugusi.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/48c63e8083fbab4a53d6e0c567450d32/gojufirovajekar.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160838054ea69c---9630030147.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/fofagawesasanupa.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16077328652da2---79972935266.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/05fe2a00d1c5397949a62e869eed94f1/manofugevegeso.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160776cb8e7a1d---56813088092.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4fe0e7735---38434969097.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160775af0f2d64---56925703212.pdfIn PDF document text
    • http://aldara-latinoamerica.com/userfiles/file/moloziduvebir.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/5221d300b25a42f59df6b4386b9b89a9/jewumofomu.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/4mr0hui3sdaf2o6qi29t7iesqt/guduvamusetojuzikikixuta.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab28c0d725---pejaxonorifegopozo.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a64150b5e6---88302889036.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/S30rS-6n6vg/uplcv?utm_term=accidents+reported+todayPDF 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_off0000d99b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99B 5124 bytes
SHA-256: 741f23e4acd2742c35c1f3b470c66c340b35f63498ed3a08c0983d7085731a29
font_01_sfnt_off0000eb1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB1F 10536 bytes
SHA-256: 0466e699f32eaf216e39118475f0a1c2c50218fbf7d54d003661c5e1db7944f7