Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c86a4e6fd0e9f53…

MALICIOUS

PDF

93.4 KB Created: 2021-06-29 00:20:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7eef07c9435b0ce0b35a3c02a8e1cf5e SHA-1: 84ba70ad51c12cf0d34e493dc559895d8a419672 SHA-256: 3c86a4e6fd0e9f53a47f9b7b5c9ce31c70e58e1ed59150f1fb4eb5adfa4f1af7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous external URIs and links to compromised WordPress upload storage, suggesting it is used as a link farm to distribute phishing content or malware. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://drafthe.ru/uplcv?utm_term=houseboats+for+rent+dale+hollow+lake
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/tjnqcjtfdevun0scc2frvspk2u/77723189650.pdf
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/t4up2oja3fmmod7aon8i5u92kr/25930566212.pdf
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/9bf9f3d47b2c942497cb8dba0f51dbd3/telotudejalutiwem.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-5-4/20210504100420580942.pdf
    • http://marketypik.pl/zdjecia/fck/file/fineveze.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/c3c477bdee5d9b3238f90d8fad2487c1/kemuvupudagotilij.pdf
    • https://healthmatters.me/userfiles/file/45803818525.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baeff71f739---danalapasij.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/qmrinhhsvlc85sdvk2a6rvtvdv/ganobubasipa.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b6b80c519---gaxoxidutanemuminulibip.pdf
    • http://osteriadelcampanile.com/userfiles/files/36672164924.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607df6ed88ca6---tafel.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16094c2c399506---30404343484.pdf
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/cec1f79e675391a1ff1eb611a310a36d/5742965935.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/409f197a2c1181b9b07f19ba884c905e/92006182037.pdf
    • https://beautyyaurient.com/editor_upload/file/sijijop.pdf
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a009912a06---venuraru.pdf
    • https://m-astar.com/UserFiles/files/26726291254.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa7c75cc97b---33357212512.pdf
    • http://agendatourvietnam.com/hinhanh/file/88086312141.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607faf92123b5---31015993716.pdf
    • http://ifa-astrologie.de/userfiles/file/64075763081.pdf
    • http://yossy.biz/userfiles/file/nuvufisimupumugagowaz.pdf
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/83a9691bf4a942bfd03af3a61febc54e/jamotexetuzuwozitogibug.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010819.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10819 16792 bytes
font_01_sfnt_off00012030.bin
b8ea43ad8a26dde44b62d8de19afe7770f509b2840e2922546fb0ccb793ac236
pdf-font-stream PDF embedded font (sfnt) at offset 0x12030 10768 bytes
font_02_sfnt_off000138fe.bin
48519583f799a981ba995ae291fb54ef677e8f60cd38848ac8ec548a1c63373e
pdf-font-stream PDF embedded font (sfnt) at offset 0x138FE 18096 bytes