Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c4c348285c9d3b0…

MALICIOUS

PDF

87.2 KB Created: 2021-06-22 15:30:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 7455208ff8b358f2396801c8429e115c SHA-1: bdef864b51b28929d2bc01555ec15ee65f1ffdf8 SHA-256: 9c4c348285c9d3b0fb5e63bb882d3a0b4caecda98cb9bea00b4f74164ab09db2
96 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised WordPress sites. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the embedded URLs are likely used to redirect users to malicious content or download further payloads. No scripts were extracted, but the overall structure and URL patterns are indicative of a phishing or malware distribution attempt.

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.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608705862ff35---388220430.pdf In PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/mbjb40t2vocupbg7qureaa4g19/monisuvogekitofaze.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/c9a41d66bd6152bb034ae82bdb4ccd3d/potoniretunolenijugumo.pdfIn PDF document text
    • http://domholidays.com/userfiles/file/69036590997.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/fewid.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/sv8kl15qu7419rshis5et9rpan/sotujuzo.pdfIn PDF document text
    • https://shidoremicrosys.com/media/18870340329.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/beab4074e5e2ca8ff18fd3414152bed0/25290367249.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/vrm4e01bguc24avtfg12tqk0qi/70427479413.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aad02b2925b---kojemifumanibi.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a38ac3f0432---rudasufepagokotirikalubi.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608faa8370ed0---gilimapabanub.pdfIn PDF document text
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/64t14mvd0dga5moa3t5ppbo7dc/guvolaturagubakabunobebu.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6a862dc1dc---datanetow.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609833c942e5b---tejupiwovilixijewunowoda.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072085885042---pogelekosepegobaja.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/nowovatagoki.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b264214d0e7---mofegutavurovowa.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/0l8f8gvb01uqijarq1lfmhkda6/98522796724.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/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=simple+and+compound+interest+formula+pdfPDF 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_off00010ff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF0 5404 bytes
SHA-256: 0249aa795f1eedc907cda937c5dc9129032130288db581968200d8dbd35ca987
font_01_sfnt_off00012234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12234 13072 bytes
SHA-256: 0f85e5cebaeb7d8587a3b22ea53951466d503b4f429600d7b3d58dbf27956172