Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d4815a8c175aa7…

MALICIOUS

PDF

69.0 KB Created: 2021-05-07 00:20:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 4a8eaca38c750c94ce38bd791aa2f484 SHA-1: bf8f3e9b57dd1c8c55ccf412de8607a49c39d006 SHA-256: 91d4815a8c175aa7cd44c9ddd10e412e383e9961e50cab4b8151a9552d84a352
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, directing users to numerous compromised WordPress sites hosting other malicious PDF files. The presence of external URIs and link farm indicators suggests an attempt to distribute further malicious content or phish users.

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 http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae216f0b33---fufamofuwofozaxipurobijox.pdf In PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/0aa820fc4d8ad58b5c65dbaeff3e8f03/65195790039.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073939207ac7---niner.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16079c61275522---kigarewamuxeziw.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16091b4a315278---61013644929.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/5149429e9732c0957bd5f330b746b01d/finexapozaj.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073d9cca7bc6---xopibiduzepapusulusu.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/886ee95245b8583fe145837aaa4aad82/38348331005.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/4f4b9e093cae5749f7fc99861723b237/20102192878.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9f3665a85---pazusetodadofugilijubav.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/ipi75kecitduq78bbsn78sps9h/69804910406.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/f1b0df87a9ecd7aa0d6ccb66db59ae94/31838593332.pdfIn PDF document text
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/cb480dbe85e0cbc8caf12971d9ec1550/64423155502.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/~3/6naE_Nh8_CY/uplcv?utm_term=maths+puzzles+games+with+answersPDF 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_off0000d023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD023 5380 bytes
SHA-256: 747d2e5e3cea98bcb760b6af8d554e074bd85a7fc1b9d9b1b1b6c1a4b95955f3
font_01_sfnt_off0000e26d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE26D 10288 bytes
SHA-256: abcd1b309fce9f4e632555a64026b74c37db1f5830ed1f849d2696f955682bce