Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c871645a58ff44…

MALICIOUS

PDF

90.3 KB Created: 2021-09-16 14:26:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2b9252e548c0be558ad61adf65070c4b SHA-1: 1893d3ed52babc6293b9d178c41f48e6fe00b67a SHA-256: a4c871645a58ff44615ee0864466e5da0bb078c149c4c7b9df5ade97e66065fa
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 high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's purpose is to host numerous links on disposable domains, a common tactic for phishing or distributing further malware. While no scripts were explicitly extracted, the presence of embedded URLs and the link farm heuristic point towards an attack pattern involving redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://beamstraffic.com/amb/userfiles/file/839020739.pdf In PDF document text
    • https://santehsevast.ru/userfiles/files/pelolutitisilotunagebabu.pdfIn PDF document text
    • http://xaydunglenguyen.vn/upload/files/e0ee72.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/lezasajatodemojutef.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/33062488410.pdfIn PDF document text
    • http://vidol.eu/userfiles/file/wokepopoke.pdfIn PDF document text
    • http://mpu-beratung-brendle.de/userfiles/file/74485095230.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/62415765334.pdfIn PDF document text
    • http://metabolizmusonline.hu/images/upload/file/gamoraluzabaf.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/sesemidagokeserur.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/furanadezaritizeduxojab.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/relojidapoz.pdfIn PDF document text
    • http://shahgrp.com/uploads/jedolelupowa.pdfIn PDF document text
    • https://sakesushimn.com/userfiles/files/29542576073.pdfIn PDF document text
    • https://edarky.net/data/file/malukajavijozopevojaxu.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/87446136043b3df6c8e9fadec6fd9232/fofesedepesag.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/torofeni.pdfIn PDF document text
    • https://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/18441491502.pdfIn PDF document text
    • https://doina.md/fckeditorfiles/file/76567313153.pdfIn PDF document text
    • http://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/xurogakokosazewux.pdfIn PDF document text
    • http://investin-khj.ir/ckfinder/userfiles/files/zamedekukizanagakuge.pdfIn PDF document text
    • http://ge-mak.com/files/69236237586.pdfIn PDF document text
    • http://risorsaterra.it/userfiles/files/97386900249.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=android+noise+sound+effectPDF 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_off0000fc7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC7C 10344 bytes
SHA-256: 0de2d878d5ffec4a491422bfb6a52a745528ad1759a2568d776711412ffccf40
font_01_sfnt_off000113fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113FD 18708 bytes
SHA-256: 647b24ed9f72fa8dd650e650e79680b203668cf71d260fb296b1ec22e754cf28
font_02_sfnt_off00014432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14432 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1