Malicious PDF — malware analysis report

Static analysis result for SHA-256 f37d0a8ae725f00e…

MALICIOUS

PDF

77.6 KB Created: 2021-06-11 22:45:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 5f54b1c717de6c70c558d789b22eae4b SHA-1: d0917284493162d1a8cd3b6e39f843f8e098d7e7 SHA-256: f37d0a8ae725f00eff76f94e2a2f9a5342fee2c68e7235b7b8361cc49717cc2b
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards the document being used to redirect users to malicious content or facilitate further compromise.

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://synerhu.ru/uplcv?utm_term=demonstrative+adjectives+worksheet+pdf PDF link annotation
    • http://s8radziejowice-paszkow.pl/userfiles/file/rebizeledupiwurexowu.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/e981fc5e273915cc189e3a716cef2d1d/43690949635.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/c012ee0e62f7654a8915b7ca39e338be/99130652359.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a356aa69511---rikukiguv.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/7ac0d958486a14dbea9c7e56b4d1d370/42587876439.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160aa1a9a79e7e---malarexegerokiwaxepoxav.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1127ce0e9---87636779560.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/14434165496.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609421965fdb8---bapisokogewepapepadu.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/e1v0rfl0athsalvmhledenko24/fakawapunudaweditodupefa.pdfIn PDF document text
    • https://giustofiori.it/file/36946524035.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/ritujojepo.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/c1b1f76d80b82a0d20be2fe7299d7f0f/35310805713.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/50p4gr0bkijbsert69ot2am0ms/kafegak.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16078f3ef0e5fa---punofizumuv.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16097553ef1a92---xewelaguremevemof.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a13568cf93f---87023282135.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eebb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBB 5652 bytes
SHA-256: 17a6b5067fff6aa5cefb8c523038c7f03730684fd8a8a9028e2809a92deb58ff
font_01_sfnt_off000101ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101EC 12196 bytes
SHA-256: 0f8e73df9c855d75011b7c7f30efe6e0cb9d3ccafd1c27e2f0cfaabaf9e67a3a