Malicious PDF — malware analysis report

Static analysis result for SHA-256 c83646a6a7a77cff…

MALICIOUS

PDF

71.0 KB Created: 2021-10-01 14:58:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4f1b492002f41a634dc180d6ed512a91 SHA-1: 11cf79f895d48de9d7bdc3408194df9ba0e29dfd SHA-256: c83646a6a7a77cffc427dbfeb1426ef8245de428e8f71e9780d44abbbb28af4c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to compromised WordPress sites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. Although no scripts were explicitly extracted, the nature of the links suggests a potential for JavaScript execution or redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615628ca54d34---37900284977.pdf In PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/qgljl51h8kmrhukr568e6qfvgh/53852192504.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/7066f050f199d31cb593ca6bf71fc1e9/jegigowubonomefewonev.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/xexawapasikemif.pdfIn PDF document text
    • https://magicdiscoradio.hu/userfiles/file/xunonojufipa.pdfIn PDF document text
    • http://markone-tools.com/upload/files/48807215301.pdfIn PDF document text
    • https://testpensija.bankai.lv/ckfinder/userfiles/files/sobonelofunevugameweteja.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/17403841002.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16135f2ab82d4f---12189138661.pdfIn PDF document text
    • http://tourgrodno.by/images/content/file/vavepifajesuk.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/nuzikofaduwukotaved.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/21033842736.pdfIn PDF document text
    • http://colorsoftexas.com/ckfinder/userfiles/uploads/73900662666.pdfIn PDF document text
    • https://tekmaker.com/upload/files/76502501288.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/wolapixexawewegakube.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613459cc6b280---39964949058.pdfIn PDF document text
    • http://www.larucheapain.fr/ljk/file/11197699458.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/7225368178.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=john+wick+1+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_off0000ae48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE48 18488 bytes
SHA-256: 10c7dfd774145528f9093e6a70339c09684aaf78420566a98a97ddd4adadcc4c
font_01_sfnt_off0000dded.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f604.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF604 10852 bytes
SHA-256: 928144ffa00b732c67cdbfa4ce8767e7d0024972bde318d39820c6b194b36fd6