Malicious PDF — malware analysis report

Static analysis result for SHA-256 141ec9f77ff7a02a…

MALICIOUS

PDF

98.0 KB Created: 2021-06-25 03:10:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 461dfe7161d38f9f86393f6528e31df3 SHA-1: f4c40d53b25e3fe172f6b0a3f2cd1064fbbd99ba SHA-256: 141ec9f77ff7a02a5552ee28c859fb40198266a613e21ffe4fc42c91fcc9aa54
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics point to the PDF being a link farm hosted on compromised WordPress sites, directing users to potentially malicious PDF files. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create documents for phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/l3i37dp6ujkvu1otr5h9f3h39d/dafugujex.pdf In PDF document text
    • http://sp3siemianowice.pl/userFiles/files/89586147826.pdfIn PDF document text
    • https://menu2uplus.com/images/file/16530566658.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160817ddb95811---xirevifa.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/3383a3fa786e0512495085dc5465ba63/gusuzosulabobofefupego.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ccfca95fb---ruloxuwupanexidiwatit.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae935b74c2---vivudomugipok.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/1oo6tuu8mlsn7qi40te46p0cia/77941469576.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abc307bf25a---zupiwomezizinerateladobo.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d9f871930---12691654698.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/52694088890.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a46dab95e41---wasaz.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607da1f26e7be---64000136754.pdfIn PDF document text
    • http://jhdljz.com/userfiles/file/1624511619.pdfIn PDF document text
    • https://tedvandergulik.nl/userimages/file/23580344200.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/goponogupaguma.pdfIn PDF document text
    • https://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/i3h7ndus3anhhh4o2g0i66g284/webagojunil.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/FevRqgeaUVY/uplcv?utm_term=old+devotional+songs+in+tamilPDF 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_off0001455c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1455C 5136 bytes
SHA-256: ff62117c2e666da5b8a8bdcf64bfe3e0e70a2731d65f7092a5f4ea2e54a02f2a
font_01_sfnt_off000156c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156C9 11136 bytes
SHA-256: c0be2eea9763896fec8b2556e6a0374c167e5b8229e1388fc0f19590d6bbe9c3