Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dc4cd370a6c3294…

MALICIOUS

PDF

82.8 KB Created: 2021-09-11 09:27:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 79167ee9d6c2db77f9e1546111d91fff SHA-1: 402899404d0e8b6d574636e4040d2aa24ba30b33 SHA-256: 4dc4cd370a6c3294a12d702cde6720f8951d5d218814cf6a6570d74ce8e3e26b
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, so the primary attack vector appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161351b680c1b3---64600116788.pdf In PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/k35hpa2jo46qi659hg8qs3nh1g/37420494732.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/65917470277.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134b0f9b0901---wulubelutuk.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16135a22ede5ea---zoben.pdfIn PDF document text
    • https://uangraja.com/contents/files/13481258752.pdfIn PDF document text
    • http://hebakotb.net/userfiles/file/3100089200.pdfIn PDF document text
    • http://recviem.ru/img/upload/kirosiz.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/46786940369.pdfIn PDF document text
    • http://jewelry-shopping-city.com/uploads/files/202109102208553194.pdfIn PDF document text
    • http://rotarybrescello.it/userfiles/files/57383375742.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/bajifovoginetaxana.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/53813249063.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16136db75ddff6---sutasatiminimuvigevizu.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/d27f8326b84eafc83f395626fa41dac2/37819210017.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/fafute.pdfIn PDF document text
    • https://penal-garazh.ru/files/dokifulux.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395a9a98264---7945555925.pdfIn PDF document text
    • https://blv.by/upload/editor/files/gomotubepiluxugogegesik.pdfIn PDF document text
    • http://trust-law-firm.com/userfiles/file/20210909224949_718414779.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/koraje.pdfIn PDF document text
    • http://medicalproduct.hu/images/files/gufez.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/28daf1286cce13fbfb764eaef87e7905/xuviwaxopuvajizopow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=gazi+live+streamingPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e064.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE064 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f87b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF87B 10496 bytes
SHA-256: 1978bcf4d774eb8c0fc3b8d65d288747de50bbc34cc17a02095806f9f17e8011
font_02_sfnt_off0001106b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1106B 17512 bytes
SHA-256: a33d12376a1563c7900fd91f709ead6647b37db09f5eec0e70f57636b1682151