Malicious PDF — malware analysis report

Static analysis result for SHA-256 625c819607c80345…

MALICIOUS

PDF

87.7 KB Created: 2021-07-18 15:56:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 167c5a5526e64299977799e600db49f4 SHA-1: 66115f1d0dac0c3a64d5730558f2046afc71405a SHA-256: 625c819607c80345aba3ab657a900db3fb8ff4a96ea1f62b917332b39b2a368f
164 Risk Score

Malware Insights

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

The sample is a PDF file containing embedded JavaScript, which is a common technique for exploiting vulnerabilities or delivering malicious content. Heuristics indicate the presence of a link farm pointing to compromised WordPress upload storage, suggesting an attempt to host malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078654850a79---71833359619.pdf In PDF document text
    • https://ludifrance.fr/userfiles/file/budesetoxopere.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/43q8qrmq5j8g98h6prap6b8lj0/9953180721.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/jixubariduwawesisaloviso.pdfIn PDF document text
    • http://eschool365.in/js/admin/uploadfiles/file/5925187575.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/41avm2cc8p0t7mnr1uk7r2dsro/tuximox.pdfIn PDF document text
    • http://arserwood.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/2105022026341447797ixe1d.pdfIn PDF document text
    • https://optimuselearningschool.com/learning/site/images/uploadfiles/69955593720.pdfIn PDF document text
    • http://xenangheli.vn/public/files/40663686047.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d5ed0bee3e8---98738944082.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160790a7844d3b---14264741638.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/67606454881.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f48c2f1ed0---8620920663.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/lodajanalenulezado.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/chkhggu3ehm26lg0j1ktklirl2/40971615371.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160e3d27618d0c---58794233124.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a35a01a1932---48017774096.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/45946569862.pdfIn PDF document text
    • https://medtek.vn/storage/file/43120232399.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/34465034847.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160713f18d12e6---68251825590.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/08e682e6601285f2e9b263b93845b21e/93516517873.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c612b3aff06---rupibatavilure.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=43+months+in+yearsPDF 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_off0000f33d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF33D 17836 bytes
SHA-256: 2e28f5e92469c213a5a366c4d2988b901b4b70d47e701fbfacb59c151d4683c2
font_01_sfnt_off000121ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121BA 10592 bytes
SHA-256: 23e3a320f40499d71e87c90c234dd6eefb6567e546fcb96d54fb1ce9a8439fe2
font_02_sfnt_off000139c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1