Malicious PDF — malware analysis report

Static analysis result for SHA-256 139982b615fa8923…

MALICIOUS

PDF

76.2 KB Created: 2021-09-19 03:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 33ca4b72d5bd1b7d2156e7903c878c3a SHA-1: bc5750293ea8eb244def9bcd593680bad9efceea SHA-256: 139982b615fa89231d27dac237243a9747cca5febf2afb25e39b03ad2de2211d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains numerous links to disposable hosting, suggesting an attempt to distribute malicious files or conduct phishing. While no scripts were explicitly extracted, the nature of the links and the detection suggest it likely serves as a lure to a malicious second stage.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://opusbiz.kr/data/editor/file/486107602613ab5305f032.pdf In PDF document text
    • http://chinasoftcore.com/userfiles/file///bitezalixuwodipamugumoma.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/zofokalalu.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/663f612c0c823088ba1cdfa17b026583/24450590392.pdfIn PDF document text
    • http://dichvutot99.com/webroot/img/files/nonixozumibelumojazo.pdfIn PDF document text
    • http://thekitchendesignstudio.org/uploads/files/54003071248.pdfIn PDF document text
    • http://rambud.pl/uploaded/file/10574906492.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/vubezobuwepozi.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/1918023705.pdfIn PDF document text
    • http://resumesfromabove.com/userfiles/file/veguvidosorugogilafudula.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/90436487962.pdfIn PDF document text
    • http://elitacasa.it/images/file/vebiguwovopuzi.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/69088241239.pdfIn PDF document text
    • https://media-get.com/userfiles/files/86769166218.pdfIn PDF document text
    • https://mimpiindah168.com/contents/files/42335557226.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/penikeza.pdfIn PDF document text
    • http://panziofabian.hu/fck_kepek/3728112266.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/70673622008.pdfIn PDF document text
    • https://medicabg.com/uploads/wysiwyg/files/senodemetunug.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/59720975740.pdfIn PDF document text
    • http://swiftnb.com/ckfinder/userfiles/files/6940850540.pdfIn PDF document text
    • https://broadcasthub.com/ci/userfiles/files/renegekegadad.pdfIn PDF document text
    • http://top-caster.com/userfiles/file/9885152776.pdfIn PDF document text
    • http://erdbau-rauch.at/32070160897.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=cpu+z+android+free+downloadPDF 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_off0000c3cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3CC 18040 bytes
SHA-256: 6b5b053abd74bca4396a0abaef3978722bd2076c8f38e2972c8b950d39ea3c3d
font_01_sfnt_off0000f2ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD1 10504 bytes
SHA-256: 36a13c83962bf77ffeb01a642e839b96f79e96e8666b2763e0adb1788052c284