Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd3c718f28c86876…

MALICIOUS

PDF

69.5 KB Created: 2021-09-30 18:04:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 33bda5df3d0470d8ef59545c7c150381 SHA-1: 65b9ee571037a14f349954b56511cf093c84b0d0 SHA-256: cd3c718f28c868769f0b6196932cc8945ab21ef80de9fb61a4cc3298d59a0763
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is part of a link farm, and multiple unknown URLs were extracted, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://stillincontact.com/images/mails/file/kefoturebugajilemukeg.pdf In PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/kumolatovetox.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/botsga7det5vb8m3uhu9ej5vd4/85449809176.pdfIn PDF document text
    • http://myphammonly.com/luutru/files/pabetowimotuxaj.pdfIn PDF document text
    • http://carnow.jp/js/upload/files/21966807702.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16149f1279463d---mibuzukazagutubal.pdfIn PDF document text
    • http://2478.ru/admin/ckfinder/userfiles/files/6052401784.pdfIn PDF document text
    • http://www.dogwoodagility.nl/ckfinder/userfiles/files/62347572920.pdfIn PDF document text
    • http://hanmih.com/userfiles/file/20210924164904.pdfIn PDF document text
    • http://blfimmobiliare.com/userfiles/files/41059648924.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/sobutuxobi.pdfIn PDF document text
    • https://chowdhurytourism.com/ckfinder/userfiles/files/40645508528.pdfIn PDF document text
    • http://immobilieninvestors.org/userfiles/file/41414837205.pdfIn PDF document text
    • https://mami-m.com/Uploads/userfiles/files/81233200236.pdfIn PDF document text
    • https://mmszke.hu/files/file/83111865869.pdfIn PDF document text
    • http://ippinnudon.com/uploads/files/zebinelodufipafiporu.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/xemorazatasunadiniloti.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/21730802083.pdfIn PDF document text
    • https://goodline.by/userfiles/file/97057313846.pdfIn PDF document text
    • https://reaga.net/js/ckfinder/userfiles/files/fedexusemepanevu.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210916_698624989E621797.pdfIn PDF document text
    • http://wadsoda.com/UserFiles/File/ralobobarigasaki.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/novib.pdfIn PDF document text
    • https://foodthings.us/userfiles/file/furigeri.pdfIn PDF document text
    • http://eichler-kammerer.de/sedunomagif.pdfIn PDF document text
    • http://ozkayalartrans.com/userfiles/file/tarobatujewimuneral.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=apk+installer+android+10PDF 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_off0000b199.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB199 10632 bytes
SHA-256: 73e98b1cab4646c2bc68f3ee18ef10d1dcd73cef62b0f9ef95f678f0ac38031c
font_01_sfnt_off0000ca16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA16 15152 bytes
SHA-256: a871656b544465d42f7aad79a684296d5abe53a580536b7fa42f7bba7f2fb332
font_02_sfnt_off0000f093.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF093 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1