Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcb627852ff40c34…

MALICIOUS

PDF

70.2 KB Created: 2021-09-25 12:13:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3c7f828b38544318b71fe5225f56845d SHA-1: 6999bc201b63eb76800576fb3fdf2a3f1c890c48 SHA-256: dcb627852ff40c341b2e2b3b45086ab03caec2509c9d1e2ddcc13d6b53e88e14
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the use of disposable hosting for these links. While no scripts were explicitly extracted, the nature of the embedded URLs and the detection suggests it may leverage PDF vulnerabilities or JavaScript to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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.
  • 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://exms.fr/sites/default/files/file/13123089292.pdf In PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/mosos.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210906034501.pdfIn PDF document text
    • https://pioneerlift.com/upfiles/editor/files/jogeji.pdfIn PDF document text
    • http://www.ambatownship.com/ckfinder/userfiles/files/91846779653.pdfIn PDF document text
    • https://syteq-pro.com/userfiles/file/33212551102.pdfIn PDF document text
    • http://azseal.net/uploads/userfiles/file/94029350938.pdfIn PDF document text
    • http://jr.ac.th/ckfinder/userfiles/files/70734059272.pdfIn PDF document text
    • http://karmakonnect.org/DrumiBhatt/karmakonnect.org/Final/ckeditorimage/files/39750178124.pdfIn PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/89920451146.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name/files/tudugat.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/jamovolidevuxunama.pdfIn PDF document text
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/birojikejujusazovos.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/72334558473.pdfIn PDF document text
    • http://bikaji.zohukum.com/ckfinder/userfiles/files/zojitubofulaba.pdfIn PDF document text
    • https://sk-elektron.ru/ckfinder/userfiles/files/gudunedigubabineve.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16147100b63185---18493841417.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac9d62ef7a---tafozonogilef.pdfIn PDF document text
    • http://luyenthidhcanhsat.com/Images_upload/files/36777685691.pdfIn PDF document text
    • http://izeninfo.net/admin/upload/files/95815445578.pdfIn PDF document text
    • http://wohntraumgmbh.at/vugelijatetixade.pdfIn PDF document text
    • http://epodhajska.eu/UserFiles/File/68238330805.pdfIn PDF document text
    • http://drigungkagyurinchenpalbarling.org/upload/userfiles/files/91431289237.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+change+country+in+android+mobilePDF 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_off0000aeac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEAC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c6c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6C3 11080 bytes
SHA-256: 96b7ea8ee84eab50a2d042e0442e26ac1ec1f0528752b082f7a8246b665a9637
font_02_sfnt_off0000e028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE028 17244 bytes
SHA-256: 663f7dff74d445a1ad65078fa4ad540b41bf4379ce7308551ef915f994defdda