Malicious PDF — malware analysis report

Static analysis result for SHA-256 d253359f161b26d6…

MALICIOUS

PDF

68.5 KB Created: 2021-06-21 05:28:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: c9746167ae51f04efd63164951bd4c02 SHA-1: ade43a0dbae728a758858e3744e2e627d1aaf4e5 SHA-256: d253359f161b26d6e9bce3b56ef664edfe4ea2e60a5a7769070f445b565b14ad
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was heavily obfuscated, preventing a deeper analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/pu60p31mto2se266c3scjhu1k7/95583887869.pdf In PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5a590afd1---20860819116.pdfIn PDF document text
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/ge1qi63a1155grirtho95p4att/lukomovekepojoje.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/iqgn9ai6alhuikq1k9o1j0qa33/ruzewotelav.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/45871249533.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/febajili.pdfIn PDF document text
    • http://dzbnf.com/upload/file/%5C/nilipofiditasisemuso.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607734ee04140---57725607181.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d692136b4a---verefe.pdfIn PDF document text
    • https://samarpanbharat.org/trila/userfiles/file/75816584762.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086e98c22ab0---31037236670.pdfIn PDF document text
    • http://www.centralperdana.com/file/jokadixosazowalipi.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/63f39bf37d7185c344261421208b7802/83873658243.pdfIn PDF document text
    • https://semut73.com/contents//files/43024791529.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/jb2rsvdepfg6iibl8o6jhq2jqf/sujozigusavunumadesu.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/~3/1KS0DP0cxss/uplcv?utm_term=lexen+tails+ffxiv+vieraPDF 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_off0000d05e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD05E 4828 bytes
SHA-256: 74877f57ec960799943f65873028a4c497d28398b5846164ab2697dd4db3a984
font_01_sfnt_off0000e0e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0E7 11192 bytes
SHA-256: 91c3c0e84411993ce4c0bd5ef77c77a9c1d20668f9c122f781417e89ab42b2d0