Malicious PDF — malware analysis report

Static analysis result for SHA-256 71f8ab4b20d80072…

MALICIOUS

PDF

73.7 KB Created: 2021-06-10 04:55:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: d0bd5eaffe4b2c85e4c85576cc4d4a1d SHA-1: 59b34629215adb0e68f4e14bc3fa20a083884bc7 SHA-256: 71f8ab4b20d80072d924f4481d128d41c872bd2c298ff3ff616e302d6b29c333
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. It functions as a link farm, with numerous embedded URLs pointing to various websites, many of which appear to be compromised WordPress installations. The document body contains garbled text, suggesting it is not intended for direct user consumption but rather to host these links. The primary attack pattern observed is the use of a malicious document to lure users to external sites, likely for phishing or further malware delivery.

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=alka+seltzer+strength+lab+answers PDF link annotation
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16080e71552d1f---foxezapokazeka.pdfIn PDF document text
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/nie6a533flknir8rdic642h807/wetukofabunupejem.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1608991ee173e6---81261316574.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/82042138037.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/b3fa6037d68a928f9dbb6351ce82a88b/22564152404.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c343ca41d---gujotexugazelixawo.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/7283297e55c7757680faf5dadd2f37b5/17608616223.pdfIn PDF document text
    • https://zanhotel.ro/beficientconsultingFiles/file/49254800560.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/o9jnlpp9rb9p79acouku4ojv06/76774588365.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/a7665a7b14a7ccee8050080216048fe4/pejenewijonagekapim.pdfIn PDF document text
    • https://powermailer.in/userfiles/file/viminixi.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/9f3e34af7ef6336a68056c809b191ed2/kejeruzugebaka.pdfIn PDF document text
    • http://vce34.ru/attachments/file/mejodusetobek.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/patilakalilufotopomatik.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_off0000e169.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE169 5284 bytes
SHA-256: 3ef1d768cc5b5e72d214490a9d8857900739863a670d95fb31c74d2950d090a4
font_01_sfnt_off0000f374.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF374 11388 bytes
SHA-256: 2e4fa6cade9fb3ac6fc9af8bb4e287e433aee6ef95f19a04d1bb0d239b022364