Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4337a673bb80607…

MALICIOUS

PDF

159.7 KB Created: 2021-08-08 18:34:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8b48a57fb210482f6d3e91e3bb5d8639 SHA-1: d4333be12fe0e8a9e7f93d3582daf6eb03e6fc99 SHA-256: d4337a673bb80607757909faf47eefe3cab2cc629cf417eaf0e14385f2c09184
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or SEO spam. No scripts were extracted, but the structure and URL analysis point to a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b30b9ae56db---7843471452.pdf In PDF document text
    • https://skillmapmagazine.com/ckfinder/userfiles/files/mojusozugutibulito.pdfIn PDF document text
    • http://jarosi.hu/files/file/sizes.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/026n7h222kbn38sgqunrd9relt/volaxaw.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/72268779262.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/ratap.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160fcfbf56ede2---12398139291.pdfIn PDF document text
    • http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084a5355102c---nulewewapozexofef.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/68369562895.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/rt85cninh7f20fo356k76v7siu/78843605123.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/56add76f87f1a5c0e812fd27e0e570d7/zidolagenifikafaro.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1610d966c803de---zafexufumezisiz.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f7e0d71735f---delaperuba.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607784651334c---tunajila.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a61f723ed86---pefawiba.pdfIn PDF document text
    • http://premsaktidal.in/userfiles/file/12680904489.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ab62ea7b025---20142343156.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/8792252939.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/luwafujexadawujoxu.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/dagorutomigaribixubuk.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/e8bcfdomem3pqce23hrn50n22o/jekixarurifudinazox.pdfIn PDF document text
    • https://www.passion-rnd.com/upfile/files/2021/07/25/tazexatowa.pdfIn PDF document text
    • http://vanhacollection.com/images/files/gajozanof.pdfIn PDF document text
    • http://geose.ru/userfiles/file/17861865887.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/85385985892.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/34062865428.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=charles+darwin+theory+of+evolution+by+natural+selection+summaryPDF 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://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_off00020ae7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20AE7 20084 bytes
SHA-256: db2a07bfbed7b90b1c8900cef5863e6a76008dcdb4ed38f88044ee6999edb4ab
font_01_sfnt_off00023ebb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x23EBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000256d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x256D2 11280 bytes
SHA-256: cc7cdb8f4b2fb0b9f7cc96353acd8f437e3b0e86928a7e6e87b507d049c56deb