Malicious PDF — malware analysis report

Static analysis result for SHA-256 b66cf4581a4f4d87…

MALICIOUS

PDF

88.3 KB Created: 2021-09-15 21:37:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4c6c8b73d216630b3b414f3df1d0f687 SHA-1: fbd4cf5b8c2363546ee15240a4dd56a5e169f60b SHA-256: b66cf4581a4f4d87d86bd80fc5eab351b70753f339a32c59ba7a6059f25a1c25
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links on disposable domains, likely to redirect users to malicious content. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristic point towards an attack pattern involving the exploitation of embedded links, potentially leveraging JavaScript for redirection or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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://abimobiliare.pl/pliki/File/jevukonubibizosegus.pdf In PDF document text
    • https://noddy.nu/images/file/favepokivojiresomomesakox.pdfIn PDF document text
    • http://fpempresa.cen.es/userfiles/files/85033703539.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139a43cc522f---69590121748.pdfIn PDF document text
    • https://sanghvicranes.com/staging/media/59401368245.pdfIn PDF document text
    • https://littleitalypizzany.com/nbloom/fckuploads/file/77128319414.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/93108003039.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/72216112423.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc45f2be45---90368862042.pdfIn PDF document text
    • https://trisyscom.com/userfiles/file/12902721237.pdfIn PDF document text
    • http://sartor.ru/upload/files/75664064192.pdfIn PDF document text
    • http://ideatity.com/ckfinder/userfiles/files/fezusok.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/surij.pdfIn PDF document text
    • https://khambenhxahoi115.com/images/files/52123483576.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/82341432523.pdfIn PDF document text
    • https://www.adoz.cz/ckfinder/userfiles/files/31992731650.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/64187205438.pdfIn PDF document text
    • http://vagyonvedelemszolnok.hu/admin/fck_upload/file/37003247956.pdfIn PDF document text
    • http://urbanposthotel.com/admin/ckfinder/userfiles/files/99197621156.pdfIn PDF document text
    • http://albertf.madteam.net/ckfinder/userfiles/files/57167580189.pdfIn PDF document text
    • http://galsabino.it/userfiles/files/82701120195.pdfIn PDF document text
    • http://umartravel.com/files/menufupatemabuzuzor.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/13889705424.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=android+studio+company+domainPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE680 10692 bytes
SHA-256: 489c1fb79c780ff09a1baff0e4e319ca9efcc52a1b9ae6a60705fd4cafaad428
font_01_sfnt_off0000ff0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF0E 2564 bytes
SHA-256: e88e50f1fb3d2eb8914f8fd6c84051aaf6b0e24badf0bd7cf812c40cb07f33c0
font_02_sfnt_off00010a24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A24 18184 bytes
SHA-256: 5ebbd3680825fd5aeab01d418e7f4b14eb6675be2c1ada569c30ba8aeda9ee7e
font_03_sfnt_off0001399c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1399C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1