Malicious PDF — malware analysis report

Static analysis result for SHA-256 98839a5a3a1ffff5…

MALICIOUS

PDF

77.8 KB Created: 2021-09-14 04:05:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6fdc4bb38a9fc746383691ff96365524 SHA-1: 8f16ada4395c114e680f370975dd7badd277b4e0 SHA-256: 98839a5a3a1ffff59d04c8493743f4797c824bba3bdee7070a0ce73242c20411
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to multiple compromised WordPress sites, indicating an attempt to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://diphong.com/uploads/bazipivetepoloxojej.pdf In PDF document text
    • http://chayka-svg.ru/files/424195078.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133e992571d8---80578035052.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/0cc3259ce30506fc83bd2e2e1f89a8ce/firunulugar.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/monigavuzukegu.pdfIn PDF document text
    • http://vibrobeton.by/pics/files/68764540428.pdfIn PDF document text
    • http://isotope3.pm-ural.com/uploads/files/xafuzopoxuvejebasetevok.pdfIn PDF document text
    • http://anpharma.net/upload/files/sagaxi.pdfIn PDF document text
    • http://agrion.org/upload/fichier/87504011701.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/30758039457.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/zibef.pdfIn PDF document text
    • http://kartelabasligi.com/images_upload/files/14821638817.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135fa24015df---lufawumalom.pdfIn PDF document text
    • http://articolo17.it/siti/usr/foto/files/77316885445.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/57907901429.pdfIn PDF document text
    • http://studioturina.com/userfiles/files/20502199465.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/3db5fe79a2c7ba4420aeebbfe8a75ef6/zujuki.pdfIn PDF document text
    • https://sukaunited4d.vip/contents/files/91744389414.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138590809208---sisutomokagir.pdfIn PDF document text
    • http://studiofapas.it/userfiles/files/maxilimaribuve.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/5246959473.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f8f86522cc---94731618502.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/70022761329.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=wallpaper+android+3d+full+hdPDF 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_off0000cb2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB2A 17844 bytes
SHA-256: 4ffa39288efdbbc71d2e669f91f7be441a08e13f65c34452249f27427895694b
font_01_sfnt_off0000f93a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF93A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011151.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11151 10596 bytes
SHA-256: f4de9f21f9edfec111d33307461d83da788e25f9a43514c470b986271e413314