Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a4246d91b635ebc…

MALICIOUS

PDF

71.4 KB Created: 2021-09-18 02:56:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 74273b4fd9d3fb66c1c950b6eb0e39fd SHA-1: 82773442e25296e4daaec384a17237d4633f970f SHA-256: 6a4246d91b635ebc5dadd21d5007ede1c6e5937dd539c80953bbb42bcd1144d4
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://vrrc.heart.net.tw/ckfinder/ckfiles/files/80317272024.pdf In PDF document text
    • https://exlite.it/ckfinder/userfiles/files/64428762042.pdfIn PDF document text
    • http://ettermanenterprises.com/ckfinder/userfiles/files/41554500710.pdfIn PDF document text
    • https://sergiomauri.com/images/file/5903290174.pdfIn PDF document text
    • https://muzpony.de/obrazki/file/39155611169.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/lusifolem.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1630951243.pdfIn PDF document text
    • https://www.zochrot.org/ckfinder/userfiles/files/75183872355.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/21777cfcbf4590f6c09e2f4d88cf9988/61171684533.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/vunabaza.pdfIn PDF document text
    • http://greenhousehotel.vn/uploads/image/files/jawulidelariwulirilese.pdfIn PDF document text
    • https://alirezamirmohammadi.com/images/upload/files/8372545243.pdfIn PDF document text
    • http://aurastaffing.es/upload/file/fugajilukobebi.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/tibudemisomasisu.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/rasog.pdfIn PDF document text
    • http://iscelenie.info/files/file/16509508683.pdfIn PDF document text
    • http://barrybusiness-crm.com/ressource/devis-photo/files/47780685115.pdfIn PDF document text
    • http://ohadalegistrocbarter.com/ckeditor/uploads/files/66841839624.pdfIn PDF document text
    • http://innotack.com/userfiles/files/darulowu.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/36441000511.pdfIn PDF document text
    • http://worldofpacifiers.com/editor_uploads/system/files/77177681980.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/lusisu.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139f56d254ef---74728618937.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/09624f8847d245eab4e8dc60de044ba6/bazukadoxafixusujogobot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=learn+to+fly+idle+without+flashPDF 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_off0000b6fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF13 10708 bytes
SHA-256: 60adbfb748a17fec61a0903eeb8fb6a5296fa7643005281062fb2863341ca976
font_02_sfnt_off0000e7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A1 15668 bytes
SHA-256: a3041f57b77d3601ee060c027843faba291242b81ee9386bde95dab8fb99783e