Malicious PDF — malware analysis report

Static analysis result for SHA-256 d85649aad4f9aca5…

MALICIOUS

PDF

71.4 KB Created: 2021-09-07 04:27:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a3cdeba2e2c2ec26bdafb110eeff6f4d SHA-1: 7183b0d0eddea8a075cade6be3f2d09562303025 SHA-256: d85649aad4f9aca50ec82919cffe61e87b82d9629337e76f658b7ecdef9ef03a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the link farm suggests it is intended to lead users to malicious content, potentially via a drive-by download or phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

Heuristics 5

  • 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://arendic.cl/files/74815454855.pdf In PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/nbfr58a0lcuhja9esv9ifg7hqp/voluruvitisugapi.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/68072953691.pdfIn PDF document text
    • http://ciskmv.com/css/file/3382056556.pdfIn PDF document text
    • https://408of53crownstreet.com/assets/media/files/woxisubaras.pdfIn PDF document text
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210712092723.pdfIn PDF document text
    • http://qapoll.com/2015/vat/upload/files/32455771995.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16088ebde41575---38370764523.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/b2b85a38f93d5b5d5bdd09ca67e24f07/rosakavakoxusokojimas.pdfIn PDF document text
    • https://coolinterier.sk/upload/files/noxaz.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/zogipob.pdfIn PDF document text
    • https://procogs.com/FCKeditor/file/27002247682.pdfIn PDF document text
    • http://bawaconstructions.com/editorData/file/dofanitinaj.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085b9eb6b92f---tirujizoxunijarop.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/38505780476.pdfIn PDF document text
    • https://doctornhospital.com/banglanews24/editorsfiles/files/mutur.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/54290548294.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/98219027979.pdfIn PDF document text
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/dc5b5c5dc318bb4a065555c1b1424ac1/fogevakulugusozag.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/916a904ac6e0b3da1727373c2f17dde2/16003651467.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f5be2f0fd26---85265355836.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/74667043010.pdfIn PDF document text
    • http://sns.hu/_user/file/35236495222.pdfIn PDF document text
    • http://www.universia.com.br/porIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=testes+psicot%C3%A9cnicos+para+engenharia+pdfPDF 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_off0000b4db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4DB 10972 bytes
SHA-256: bef3b1170f24ff8ddcd4f591d2187c6db42ab962a62fc8e8283412407dc01c2a
font_01_sfnt_off0000cdc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC0 16788 bytes
SHA-256: 6e20707105efb58b477440d7c3f4cb934bbc7261b3acc344181b8603a6be28c9
font_02_sfnt_off0000f5f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1