Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9ff6bf57a4022fd…

MALICIOUS

PDF

68.0 KB Created: 2021-09-19 15:47:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 11d95caf6cfe1aff4b11d24ce05abf97 SHA-1: b2335d03535f2434c37679a3deec726a897f3b14 SHA-256: a9ff6bf57a4022fddaa0bf411f1d8602053222c0cbd74b4046aa9bd89a5d2fbf
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised WordPress upload directories and 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 external resources. No scripts were extracted, but the heuristic firings and URL analysis point to a common pattern of using compromised sites to host secondary payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://huntic.ru/uplcv?utm_term=rog+5+antutu PDF link annotation
    • https://plagij.at/ckfinder/userfiles/files/vibomufilotana.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/pububurizome.pdfIn PDF document text
    • https://skykharchono.mn/editor/files/zizidotuzepadorimapabiz.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89790160632.pdfIn PDF document text
    • http://wefocusdesign.com/upload/files/vakosebidadodan.pdfIn PDF document text
    • http://curvesncontours.com/userfiles/file/dijagofavefalazedurimabus.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130688ca1554---63529546538.pdfIn PDF document text
    • http://zatacorp.com/upload/files/89924565808.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f057bcdd67---66799221565.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/tefapixogutujixubo.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/40072897294.pdfIn PDF document text
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/zezexozadaluredimizota.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/29178767443.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16140931bcf678---74351280331.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/fibefogofusabuwugoluvote.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/82911147309.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f4a9a1bb8---wubozapavopuvifezipufun.pdfIn PDF document text
    • https://uclerbaklava.com/resources/file/pirolusaximodoto.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/vomijonokizimilulekudi.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/24371779792.pdfIn PDF document text
    • http://ehomerealestate.org/images/file/88013188461.pdfIn PDF document text
    • http://xz-brand.com/ckfinder/userfiles/files/95584860401.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_off0000ae40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE40 15328 bytes
SHA-256: 35498d35c3d8a2a22536ad9760249ace4b912973f98bd5cf78cb4741a07358a4
font_01_sfnt_off0000d470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD470 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC87 10024 bytes
SHA-256: a8ffc423e0c5ca3ef9ca94b8e419deebb5c63e0df1731a38d0779fd4cf68387b