Malicious PDF — malware analysis report

Static analysis result for SHA-256 c63de7c55e3c96c5…

MALICIOUS

PDF

89.3 KB Created: 2021-08-09 13:59:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6e4ecdcd3915adb0ccfbe45826076d5a SHA-1: 1f4b71b7c552d771a3ebe03a048dafc7d91544d8 SHA-256: c63de7c55e3c96c55af3566c0464fbc12d79c4b645a47fbd90ea9f781df049e9
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://thietkewebseo.com/webroot/img/files/dovovenorezosinato.pdf In PDF document text
    • https://bio86.net/fichiers/lekurotemabugefozajotod.pdfIn PDF document text
    • http://vitaminyplus.eu/files/file/6397535928.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/58021631871.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/sebosir.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/konarojelerepumemipukuti.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/3ftkv3t88tb2t2jo99mg8se0bc/nosejukiwupokakixo.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/82178351974.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086067e20bb6---tozilovetom.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/126eb6efd730cbc85e3cc63778837613/zesifojuwatow.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/0f5fba57552b5e236c953a4edbccfe0a/81965600358.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/i2e2uvo37f8tqlg56ssb04og63/4523366751.pdfIn PDF document text
    • http://nacyc.jp/Upload/file/49337155772.pdfIn PDF document text
    • http://samtekelektrik.com/files/xexulafirumum.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/4056727278.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16074b4f27da8b---4029646699.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610b07ab63ef9---lorakiwutosiregiketijujun.pdfIn PDF document text
    • http://salt17.com/userfiles/files/60047024600.pdfIn PDF document text
    • http://briarcliff68.com/clients/71184/File/budozukik.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/a652efc378717e21b99cde5ab2f388b2/76212978370.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c636f0027f8---nakerixilifakokimibakud.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/c05c5bacb2d357cac99cc8da7a305c71/13884879919.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b54bb360976---59815476095.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/8cf2ffdb399b625159c977644f3bf4e3/sofamuxutori.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/6440c78ec17986065d8a2e51fe761483/7150056185.pdfIn PDF document text
    • https://vongtaytramhuong.vn/upload/files/55300484224.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=fisher+paykel+fridge+filter+changePDF 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_off0000f89f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89F 10960 bytes
SHA-256: b2fd7a45d8e10e6c1df7ff77521ac35eb20273337e7390121e2599c72eff3f44
font_01_sfnt_off000111cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111CD 17220 bytes
SHA-256: e5f7c2f371f172e0842522e263c58ca4642bcc351d726cba5cc94dda76e2d732
font_02_sfnt_off00013eb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EB2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1