Malicious PDF — malware analysis report

Static analysis result for SHA-256 401c6d75dc3aa7f7…

MALICIOUS

PDF

68.4 KB Created: 2021-09-20 17:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5025707dbfe49b85cdab8772f5d83b2a SHA-1: 02f91d583a5d61dbf9049ec8a92b90fdae269d48 SHA-256: 401c6d75dc3aa7f7b3bb8d9d7ef319c1e52ebf124c2db46c387b01518643582f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://synerhu.ru/uplcv?utm_term=disgaea+4+android PDF link annotation
    • https://brihat-group.com/assets/userfiles/files/18365047834.pdfIn PDF document text
    • http://agro-vostok.ru/userfiles/file/86793287713.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613621cfca908---sibodinerok.pdfIn PDF document text
    • https://piti.leaddeehub.com/userfiles/files/rulafenitilenumogu.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/94730659906.pdfIn PDF document text
    • https://inprovitchile.com/ckfinder/userfiles/files/nitedujewolamokodu.pdfIn PDF document text
    • http://1-sanya.com/blog_images/blog_/file/letigalugafamipopalosebi.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/4e0903ecaf6f023266a0355c5f486926/23357785924.pdfIn PDF document text
    • http://spielundlicht.de/content_provider/documents/files/fatulozeniwazidodetiva.pdfIn PDF document text
    • https://vespaclubcagliari.com/userfiles/file/99996354286.pdfIn PDF document text
    • http://shinaval.ru/userfiles/file/rakogezufut.pdfIn PDF document text
    • http://csc0351.com/userfiles/file/20210908183812_5zjvfk.pdfIn PDF document text
    • http://polletnv.be/uploads/files/57184244942.pdfIn PDF document text
    • http://iviltra.lt/images/files/28550908159.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/17661409828.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210907_064440.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613097a0cb56d---vuvitodapojaganagekexalo.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/gopalugab.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/fejipusezaxenufeboxoneles.pdfIn PDF document text
    • https://uangraja.com/contents/files/76838932915.pdfIn PDF document text
    • http://realestatemiami.com/userfiles/files/1714904045.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090905235645.pdfIn PDF document text
    • http://capableapp.com/uploads/files/xojevivali.pdfIn PDF document text
    • 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_off0000b0d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0D2 14364 bytes
SHA-256: f959abfdd2888ea6a1a404ef9d31c0e2263d6ddc477a4bbba62e732144798c32
font_01_sfnt_off0000d4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ecdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECDF 10356 bytes
SHA-256: f1f55ae49cf7020bf4edcfd8140d689121d134c563e0ccdd11d731e28f7a584a