Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d9400d5d52932e…

MALICIOUS

PDF

81.9 KB Created: 2021-08-16 16:57:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6bb905046b2acd451d14d0ce706f6ffb SHA-1: 2827beb4bba91b097ddde765cd3fab55eb55bf2b SHA-256: 88d9400d5d52932e4a0bfa6ad70768d5d49f8e376ea0b0342ab5669a6c69e3dd
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to phish users or lead them to further malicious content. The file's structure and URL patterns suggest it functions as a link farm designed to exploit SEO vulnerabilities or distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160fc4e5222460---tepulo.pdf In PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608b0efc53c1e---28544652158.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c578169a27a---xateli.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a49bc760eb---xutudimajamotale.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609773ff59b8f---finagiwebevukiw.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16087de5a37c3d---63207755943.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/mavakukejetowaxekuposij.pdfIn PDF document text
    • https://centrosteadycam.it/wp-content/plugins/super-forms/uploads/php/files/d0295aa7bb41d3a4a71b8053a17c4d23/71599725439.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608681aa972c1---duzeto.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/49662403248.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/votutade.pdfIn PDF document text
    • https://forthepeoplegov.com/userfiles/file/63609333865.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/7ea856734c2d574e74fd90fb2999718e/xakemedun.pdfIn PDF document text
    • https://at1-turbo-j3t.com/contents//files/23296273152.pdfIn PDF document text
    • http://moorheadhigh1970.com/clients/c/c3/c3beaea4c2dff0dfe15f0c96d12524a1/File/96496220140.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=el+libro+de+san+cipriano+pdf+gratisPDF 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_off0000d784.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD784 18400 bytes
SHA-256: 56191e031eae090c224cb9a9ab1c47e05b85c53f44555b0beb8f88a7dc3a9eaa
font_01_sfnt_off000106a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011eb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB8 10920 bytes
SHA-256: 793b3e69ff9f3a06e35f41a58ee0121dcf7f38c189b0a2159117bb16567d5d92