Malicious PDF — malware analysis report

Static analysis result for SHA-256 9538a59f4565a1f0…

MALICIOUS

PDF

89.0 KB Created: 2021-07-27 19:24:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2c8338f45849473b573f15c830eeb5b2 SHA-1: 9f343bdcf4589c3de3c864a5cd7bed763c97331a SHA-256: 9538a59f4565a1f0d5952faa211aa42a1e90f99a6cbdc9817e08a47e0f72c793
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm used for phishing or distributing further malware. The PDF structure itself is also flagged for suspicious link farming and duplicate object bodies, further supporting its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://thefarmatarapahoecounty.com/userimages/susawu.pdf In PDF document text
    • http://gemculture.com/userfiles/file/33748388601.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/53b8k4ge7lhpn6nik6h9mq2p56/91465716380.pdfIn PDF document text
    • http://bvmnotarissen.nl/app/webroot/files/ckeditor_files/files/tewevafoveve.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/r2hds7bk47iit8hu6q4vat4e63/mumovet.pdfIn PDF document text
    • http://biomehl.com/images/content/files/8659093160.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609106e431fad---poganubunerezumupukepeta.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/67311503637.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/46795370344.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/7076297196.pdfIn PDF document text
    • http://nctpa.biz/clients/5/51/51e593b678cc4707ea5ff7b662bcbdb9/File/tugavukezukubosive.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/772c5a31ecdf4ed5590c0e01aa595fde/xinunovuludupuzasetubu.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/hmralga1f56dh74d9vdob1g5sp/xokizasajetolamexewovit.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/woronexewuvawita.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/75gfkf71t99vpp2prdfrml90aa/34969198652.pdfIn PDF document text
    • http://vuonlan.vn/data/upload/files/gebukefodimo.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/topuxosisaxovinadewidap.pdfIn PDF document text
    • https://termofriz.rs//files/1930921946.pdfIn PDF document text
    • https://www.albispanaderia.com/wp-content/plugins/super-forms/uploads/php/files/80587619c4a2339505edabea1a3c3408/xudexanefilelivena.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e0dcbdb97---100960347.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0090793ce8---dugudeb.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16094e119886e2---36017428405.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077206b6fefb---gerenoxadiwoxerumoguk.pdfIn PDF document text
    • http://quatanggiabao.com/images/uploads/files/lozepeninisosifekarodug.pdfIn PDF document text
    • https://grupahatak.pl/admin/_fck_files/file/vogejuzifumugefufejo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=minimo+comun+divisor+de+8+12+y+20PDF 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_off0000f3b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B3 18608 bytes
SHA-256: 1c5b59cf099c40a99bbdd196c3c5871ef92a7a69b1f3a7f991c5da9087583255
font_01_sfnt_off000122c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C8 11000 bytes
SHA-256: 4576786f8bd128e36c267cc0b06500eceb76a817afa205ee8f4027cd8c520d7d
font_02_sfnt_off00013c6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1