Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff3893fa2491494e…

MALICIOUS

PDF

68.4 KB Created: 2021-05-03 10:50:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 14d3688493f5ee62aceb95d9fc2ec923 SHA-1: cb32b7c3746c57237064a7ff7f76f11abf54489b SHA-256: ff3893fa2491494ef51a2b564381258505b54f0030d030f59cba6755b51e1f1b
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, specifically flagged as Pdf.Phishing.Trojan. Heuristic analysis indicates the presence of a link farm pointing to compromised WordPress upload storage, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated, but the presence of external URIs and the overall structure strongly suggest a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16079d03fe2efc---87329686170.pdf In PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/b7f84f7b4531698833d70df0bb73c1d6/13904893485.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160758d3b546fd---67683717312.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca95da306c---74894898416.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607037c730f1f---dafuwiwaberozafegegado.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/rmvbv34ghqt0opmbdeifkkej8d/jirerofuzevifuregu.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075412a676ae---rikaluwimivemozan.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e7eb425410---15436891992.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/hpq4ufveeghtpont5f4fme0p6l/64500575906.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086624b1457b---82656285849.pdfIn PDF document text
    • https://www.sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/16086387c37c51---dikoporixisixonefeke.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160855cf49014d---47909929382.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16075e3171bed2---91741065068.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/4fd54bc590bc0038424119751d1b95ba/93053684176.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=aldinga+beach+primary+school+uniformPDF 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_off0000cf99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF99 5800 bytes
SHA-256: e9b34b29b47cbc92170f6daf0c78f8418efe14e28c9b0b40e3ee55f403e65f57
font_01_sfnt_off0000e331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE331 9940 bytes
SHA-256: ed8995753297d737fe769ac4fcade5151cb4c177556cd7ec64dbf93c33ed6196