Malicious PDF — malware analysis report

Static analysis result for SHA-256 311f23b529909232…

MALICIOUS

PDF

83.4 KB Created: 2021-09-01 23:17:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 337a83c7d696105a0d3974de2e280d91 SHA-1: 5f7a910db7cfce861b0fc59cc384ec5204f7b369 SHA-256: 311f23b5299092325f437a07905844e0a06855c7e51c2f01a67e24d8b8e530a4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript, which is a common technique for executing malicious code. The file also exhibits characteristics of a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The ClamAV detection and ML classifier strongly indicate a phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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.
  • 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://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab20616fb50---medejunirujofinediva.pdf In PDF document text
    • http://papinchess.ru/userfiles/file/79688452798.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607b57db412ae---tojedaledubumoges.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160841e72d4438---wudazipawi.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/65429218121.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/duvomopozepovifo.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/00602aa04308cf8dc17944e0037fa690/78839591149.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf504a0c59---56201842006.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c21974f655---81048083950.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/38253295813.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/6812882250.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210827110133.pdfIn PDF document text
    • https://paidionresearch.com/userfiles/files/saremaso.pdfIn PDF document text
    • http://gunjanjain.com/app/webroot/js/uploads/files/45787243908.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/vuzovuwojamovugoritibiro.pdfIn PDF document text
    • http://viswinkelindex.nl/images/uploads/towefe.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/40606996149.pdfIn PDF document text
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ropatikivesuzuziduguwewo.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073156ad116c---pitegabufesilapelarutig.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160982b9682b10---wunifovetoxuzosino.pdfIn PDF document text
    • https://bruceautoservice.com/files/file/jikizazigedobojozive.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/t5n8i0ea4ljsjh5p3qg7c577th/zanenugot.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/19396052620.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=what+is+scientific+reportsPDF 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_off0000df09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f71b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71B 18668 bytes
SHA-256: 3baadbb69f8729b766847503793e004cc9d232b48f93fbc2f21cd3b42740a740
font_02_sfnt_off0001281c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1281C 10524 bytes
SHA-256: 97b24c6d0f3cb57be6ef242c9fdaf3129a115f9ebf382a49d4f01327d16a2a29