Malicious PDF — malware analysis report

Static analysis result for SHA-256 103d13ae79a68475…

MALICIOUS

PDF

89.5 KB Created: 2021-09-17 09:52:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f73702c0e60d45e1df590a5309230391 SHA-1: 362cacd617301c2476582972d0c89089a34d3eb3 SHA-256: 103d13ae79a684755a1635a618bd9f894fab45b7e3ae5a9c4fd4c1193fce0ee8
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and numerous external URIs, many of which point to disposable domains and are structured as link farms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript suggests an attempt to execute code or redirect the user, aligning with the spearphishing attachment tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nsmpublicschool.org/slbdavbatala/userfiles/file/92216045348.pdf In PDF document text
    • https://bazab.ru/ckfinder/userfiles/files/6416993832.pdfIn PDF document text
    • http://lrpharmaceutical.com/upload/files/82731935788.pdfIn PDF document text
    • https://swift-tw.com/lcc/upload/files/riwejilewudejogasedekuge.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/roridururi.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/65209242417.pdfIn PDF document text
    • https://galaxy-training.com/userfiles/file/65596924026.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/katogudonetoxigaz.pdfIn PDF document text
    • https://digireg.cz/upload/vaxinerivirabogukoraj.pdfIn PDF document text
    • http://opersan.com/file/68576123962.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/57888282072.pdfIn PDF document text
    • http://rc-mst.com/mst/_upload/files/dolevejimu.pdfIn PDF document text
    • http://mijn-nederland.nl/userfiles/file/76520241615.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/sirijibamevaxafotajepif.pdfIn PDF document text
    • http://www.idukkidiocese.org/files/js/ckfinder/userfiles/files/40965464075.pdfIn PDF document text
    • http://origo.ws/userfiles/file/35497488102.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e516d1baa4---narikamuropuxibizotuvifeg.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/5584684630.pdfIn PDF document text
    • http://www.kigimex.com.vn/ckfinder/userfiles/files/46975897161.pdfIn PDF document text
    • https://mma-montessori.com/admin/ckfinder/userfiles/files/23714654938.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/a2e5f2f8bc68745fd07837de9c2855ab/savase.pdfIn PDF document text
    • http://tatagz.com/uploadfile/files/54377691320.pdfIn PDF document text
    • http://eko-uklid.com/files/file/telapulavibog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=hack+android+device+using+metasploitPDF 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_off0000f40c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40C 19244 bytes
SHA-256: 8a553d51723a260beefefd04e8217dfe13cd52851dc46d3b5c39613f7670460e
font_01_sfnt_off00012657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12657 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013e6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E6E 11108 bytes
SHA-256: fbdeaca600f9e62457b84daf1605fbd2ae551ca60627466499e419b2cd40a777