Malicious PDF — malware analysis report

Static analysis result for SHA-256 854c8bfb07436910…

MALICIOUS

PDF

71.4 KB Created: 2021-09-15 20:01:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fa20275ec8fc546079e5aba231e8b1cc SHA-1: f8a45a0723d99ee5b166085b729f1ebaf1ebe85a SHA-256: 854c8bfb07436910ca03d69ab22ea84bc635da3f9e09f609932e72d0da863a44
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to websites hosted on compromised CMS platforms or disposable hosting, indicative of a link farm designed to lure users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The file's structure and URL patterns align with common techniques for distributing malicious content via seemingly innocuous documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://studio-castiglioni.com/userfiles/files/30998369252.pdf In PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/rewemipovukalopesuriman.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/tunoremivagedapit.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/2d0e41c22e6efd48948ee560cd912be7/wowebepibodi.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/48123732254.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/97138518031.pdfIn PDF document text
    • http://blevy.com/ckfinder/userfiles/files/bodelobatolubusafiluz.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/31032502134.pdfIn PDF document text
    • http://otpetye.com/images/shared/file/jazafipufamawibanapisa.pdfIn PDF document text
    • https://bartonsteel.com/tony/barton/ckfinder/userfiles/files/suzojutomosubolo.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/g8l026dplt39aep0qvdufpkrat/99705212791.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/161414afe5a7ed---zofedexofoxagenejovu.pdfIn PDF document text
    • http://kamerton.nl/clientfiles/5433125049.pdfIn PDF document text
    • https://guptajimarriagebureau.com/userfiles/file/6495100475.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/33382145529.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/77920539424.pdfIn PDF document text
    • https://calendarsunrooms.com/userfiles/files/wemarinefinadukukil.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/fovekiresakosaselutodi.pdfIn PDF document text
    • http://www.moyekolodin.com/files/bewikuwiruxevaz.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/47051853191.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/boxolitomaxojarimukidaguv.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/furete.pdfIn PDF document text
    • http://skisun.it/userfiles/files/zusofokawe.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/kuleju.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaae184612---livaza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=best+website+to+watch+tv+seriesPDF 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_off0000b5bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5BC 10520 bytes
SHA-256: 5889aba87238bba962b564a6535d6e28f8f65b39ecdf6bf4d715c6540e50fab9
font_01_sfnt_off0000cdfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDFC 16388 bytes
SHA-256: 355fa35feaab2aafaf6fb5c42a8660f7e3d32c9c716a3e7b0edece04fd58800f
font_02_sfnt_off0000f7f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1