Malicious PDF — malware analysis report

Static analysis result for SHA-256 c639cd1633805ff3…

MALICIOUS

PDF

75.5 KB Created: 2021-09-11 05:05:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8c3cee9eaebf0eeae52e39cc2fc8ff50 SHA-1: 13a5c6e02187e24f2566c6ae558583ffefc06e4e SHA-256: c639cd1633805ff399a5e9f8df0acd42cfe3fa57f43cc8db8eff08f08fc348a0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a phishing or malware distribution campaign. It contains a large number of embedded links, many pointing to potentially malicious domains, suggesting an attempt to redirect users to harmful content or downloads. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further indicates a deliberate attempt to create a link farm for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://youil.org/userData/board/file/pekorevupelu.pdf In PDF document text
    • https://efficientinfocomm.com/ckfinder/userfiles/files/76567943824.pdfIn PDF document text
    • http://csptech.net/admin/userfiles/file/biwesojodarowopanamanaxor.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaced521a9---xadup.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131a6704deca---94485396937.pdfIn PDF document text
    • http://muacuoi.vn/Pictures/files/wakolumod.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/xegiwopegufuvutoxodefi.pdfIn PDF document text
    • http://www.520amis.com/upload/files/47860617782.pdfIn PDF document text
    • http://ilkemymm.com/image/files/64651412562.pdfIn PDF document text
    • http://irk-yoga.ru/upload/files/tozif.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/7118732951.pdfIn PDF document text
    • https://begili.com/uploads/image/files/wijevazibasodidebu.pdfIn PDF document text
    • http://namadagaskare.ru/ckfinder/userfiles/files/5952981898.pdfIn PDF document text
    • https://gujaratisamajparis.org/upload/files/lodigamujenelagumetusazi.pdfIn PDF document text
    • https://ijfbacknumber.com/editor_up/sagatovodesurakedaxo.pdfIn PDF document text
    • https://ispartaprefabrik.com/ckfinder/upload/files/tepegowolisubemasusir.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/3326230991.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210904153139.pdfIn PDF document text
    • https://letstravelforacause.com/miet/assets/files/zirej.pdfIn PDF document text
    • http://avtokapriz42.ru/userfiles/file/noxave.pdfIn PDF document text
    • https://pearproperties.in/userfiles/file/3463857562.pdfIn PDF document text
    • http://dungcumaymoc.com/Images_upload/files/35828169475.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=descargar+kof+para+android+apkPDF link annotation
    • https://www.posluh.hr/ckfinder/userfiles/files/97320494123.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_off0000c164.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC164 10744 bytes
SHA-256: 0049bfdd078affdb862a0a678d31f0acbc95fcc7555d9d333b75925a89294ec4
font_01_sfnt_off0000da04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA04 17904 bytes
SHA-256: 8be1ca5f99bc3594e64792ef9ac970422f3f9e46f6bdcf47a6bbce1057e22b52
font_02_sfnt_off00010806.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10806 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1