Malicious PDF — malware analysis report

Static analysis result for SHA-256 99a22b16d0357360…

MALICIOUS

PDF

71.5 KB Created: 2021-09-21 09:34:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d83f156450110b616027069a3ba0b31f SHA-1: 95bb775524545f4c5ec10bac0e8eae25cf78138e SHA-256: 99a22b16d035736096f3e6cb212b358ef1377fbcda47f610c896de70a65a1f4c
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan PDF. The PDF contains numerous external links, with several pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The presence of these links and the nature of the detection point towards an attempt to redirect users to malicious content or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://isigakizima.net/img/tmp/file/28363385672.pdf In PDF document text
    • https://shinaltd.ru/images/file/28676760186.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/35608346874.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/15646695760.pdfIn PDF document text
    • https://learn-atdi.com/uploads/files/46631144198.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/gilimisitebofepelipanorap.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16148fa82c2ec8---40345090414.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614028b102c0f---49085688520.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143668be177d---xugupowa.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/38948335745.pdfIn PDF document text
    • http://lamarchesainterita.be/lamarchesainterita/imgdb/news/files/pazosemobutulex.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/litexelajew.pdfIn PDF document text
    • http://masterref.ru/editorfiles/file/perijugobi.pdfIn PDF document text
    • https://podimercrm.com/img/files/40136529894.pdfIn PDF document text
    • https://hunde-katzen.at/soubory/15368977026.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/85393969a7a41b905046b30d0cbe9c2c/kegajikiluwitiwikimewasi.pdfIn PDF document text
    • http://jfhconsultancy.nl/userfiles/files/54091918714.pdfIn PDF document text
    • https://sharedsynergy.com/userfiles/file/daduvixavususisadikip.pdfIn PDF document text
    • https://watfordfairtrade.org/app/webroot/img/files/16320521185.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/xusav.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/depizaroxugi.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/rilijeputa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=best+background+change+app+for+androidPDF 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_off0000b45d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB45D 11240 bytes
SHA-256: bbfa88d134c181dcc197a6a54f25e3a8cf5e47240dd7cfff8ab318c5b9d87697
font_01_sfnt_off0000ce4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65E 16360 bytes
SHA-256: a2544d44d7be4ddafe12e4fe5f42a90154945ac6549595f11820c22afd80a4ea