Malicious PDF — malware analysis report

Static analysis result for SHA-256 16a883633fc3c47a…

MALICIOUS

PDF

70.0 KB Created: 2021-06-22 09:22:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 89d29d802088cd5e7a6f688383ae0740 SHA-1: fbd25e7574fdcab66b5b657a0f7234756e509a37 SHA-256: 16a883633fc3c47a6aea4b6b82370c79ec2115956e36305dda15b4ff06e23ac0
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it's used to host or distribute further malicious content. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'unicode doc converter', implying a lure to disguise the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074805a9ca1e---28222307019.pdf In PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f88dc6767d---78987157365.pdfIn PDF document text
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/luzalomumofafuluvulew.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/nebisawaxevujogebevexite.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/anj1am0b7ml2pse5rvccv3p8cd/luriwenazuseguxunexa.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/hfvqivgdmrnao239nbt9fi8npo/vivejeni.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/e50ecc8befb1f121d22bcd3fe3de7907/posulawurazobelinalugak.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebbc65bb46---47405317672.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b342d90c540---rigimutanefuwelurejub.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/4a998bae68542d1f5390f5361239544b/87629012867.pdfIn PDF document text
    • http://domholidays.com/userfiles/file/sulofexumonabeza.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/414172967a81c8ecc128c2fb1a93f514/fugewas.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/toxajawe.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/461b26238d1600952f7195bc2e15f18a/kuxizasuzonujoxuziwadipen.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/59e0c9e870d35c64ad1b034fc4299978/wewidewefurebata.pdfIn PDF document text
    • https://digidatadecolombia.com/wp-content/plugins/super-forms/uploads/php/files/299e54a3f3e8b67deb3e0f222a28af9f/68383871141.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/cv9VXjIrmdE/uplcv?utm_term=bijoy+to+unicode+doc+converterPDF 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_off0000d597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD597 4800 bytes
SHA-256: ddaf67cb44242f7768a8a83d5f83ffb205607416230984302f97e5df9f28e83a
font_01_sfnt_off0000e610.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE610 10792 bytes
SHA-256: 5ff32a60bda6150e4a3fb453daf24c4b05410d819ab3cfc08b770a4b8247fd24