Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ff4add5f7589b07…

MALICIOUS

PDF

72.8 KB Created: 2021-10-01 06:23:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: ee2887df5e339ed92926d64fef887238 SHA-1: e3305437ac8dc7d91f207ad9c16bc9056cbf169a SHA-256: 3ff4add5f7589b076cdd36ce48f25753205702ec1be7053693a835c72daea88a
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates it functions as a link farm, directing users to numerous distinct hosts, which is a common tactic for phishing or malware distribution. The embedded URLs, despite one being marked benign, suggest an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 5

  • 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.
  • 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://fisioterapiasuzzara.it/userfiles/files/23903311569.pdf In PDF document text
    • https://xuantruongtech.com/images/ckeditor/files/xumoritepebadinopetor.pdfIn PDF document text
    • http://porpora.group/imagenes/imagenes_contenidos///32383732168.pdfIn PDF document text
    • http://cn-noah.com/uploadfile/file/sibebafotofifivozijuzap.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/satixixitojisapuk.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/gbe7nr0pctl4g1gmcqva3sar2q/62596175558.pdfIn PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/9646017520.pdfIn PDF document text
    • http://heatherjansch.com/ckfinder/userfiles/files/vibagumogodu.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/30589029313.pdfIn PDF document text
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/sewimezamododawipujir.pdfIn PDF document text
    • http://christopherdallo.com/file/45019685593.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/76072548525.pdfIn PDF document text
    • http://bixenony.com/userfiles/files/4285612828.pdfIn PDF document text
    • http://inggeo.eu/userfiles/files/vinifixisosolemifof.pdfIn PDF document text
    • http://tongshengchem.com/ckfinder/userfiles/files/doxasogafagonuzifik.pdfIn PDF document text
    • https://silverstonedevelopments.com/ckfinder/userfiles/files/firifuvonujaki.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/jokebavikaro.pdfIn PDF document text
    • http://kiajihlava.cz/UserFiles/File/56844623327.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/1c07c1cf4f553c38156c485758f69ca7/15691963978.pdfIn PDF document text
    • https://haysalon.com/public_html/userfiles/file/36935564937.pdfIn PDF document text
    • https://www.pirkitpadangas.lt/ckfinder/userfiles/files/48118234007.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+send+file+from+phone+to+computerPDF 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_off0000b698.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB698 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ceaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEAF 10900 bytes
SHA-256: 7ae1539231acfaf76d460c6e87b5b9d578bf378c1c1ffa505ebf4a6d011b4c52
font_02_sfnt_off0000e7af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7AF 17668 bytes
SHA-256: 83bf240c0f49a94d3f5c4eb4c959ff68f5231307e1f6c05926ac1e3b9a649512