Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f16acdbfdb2c74f…

MALICIOUS

PDF

74.2 KB Created: 2021-09-10 12:14:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fb39844f474918c81d6f64dc9fa47e5f SHA-1: 1b4410b1fff2533e286397e30128fe2f23e7eeb9 SHA-256: 3f16acdbfdb2c74f406a42bfa4ffecaf2767209f28915e2a53228cca19b85a60
142 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or delivering malicious content. The presence of numerous external URIs hosted on disposable domains, coupled with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, strongly suggests a phishing or malware distribution scheme. ClamAV detection and ML classification further confirm its malicious nature, likely involving exploitation for client execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://smidgel.ru/uplcv?utm_term=tunnelbear+mod+apk PDF link annotation
    • https://12shio4.com/contents/files/navusemagedakivijuxeta.pdfIn PDF document text
    • https://kenkochaya.com/user_data/ckfinder/files/13200832151.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/43542071604.pdfIn PDF document text
    • https://doxity.ro/ckfinder/userfiles/files/kaxisukunolofezam.pdfIn PDF document text
    • https://alusol-kw.com/ckfinder/userfiles/files/fosiwurakubokamabus.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/rixukidokivi.pdfIn PDF document text
    • https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/18177194730.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021090401115480554.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/97892420746.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/30861405954.pdfIn PDF document text
    • https://33mobility.net/uploads/files/vokekorototiwuf.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/vuloburenudakovut.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/89158967338.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f45f811ee4---64156879036.pdfIn PDF document text
    • https://www.prieur-equipement.com/ckfinder/userfiles/files/74051039381.pdfIn PDF document text
    • http://tbvshungviet.com/upload/files/lafuvelukavekidovisip.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/16130f5ac8f84d---91798498167.pdfIn PDF document text
    • http://statsale.com/data/upload/ck/files/23995976041.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/73256157882.pdfIn PDF document text
    • http://ducthoaudio.com/upload/files/benam.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/65098024942.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/vubiwokoxifizi.pdfIn PDF document text
    • http://www.ernakulamarchdiocese.org/www/js/ckfinder/userfiles/files/ladobosodokatezivum.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_off0000c23a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC23A 10488 bytes
SHA-256: cae9f888f5b77b778a65dfa100cefa0d202d78c16a9fa380b3c963eb2d313010
font_01_sfnt_off0000d9c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DB 16160 bytes
SHA-256: f9e9b7a2d0237a654125e04ef962eba726f582da3c182c4692820b85bb96e8e1