Malicious PDF — malware analysis report

Static analysis result for SHA-256 66aecdbaa825a2f5…

MALICIOUS

PDF

73.6 KB Created: 2021-09-23 20:24:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 36f48a091e6cb9b3e617f1e1fad77943 SHA-1: 94fe64ee41959ab9c22ef0f7a783ff2c14fea878 SHA-256: 66aecdbaa825a2f55ede3d1a9b1778610d83f572bef915623991a1f59b4e53c2
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, specifically as a phishing trojan. It functions as a link farm with numerous external URLs, many of which are hosted on suspicious domains and point to other PDF files. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a pattern of using many distinct, disposable hosts to obscure the true malicious intent. The document body is unreadable, suggesting it may be obfuscated or contain only metadata.

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 https://saksisan.com/upload/ckfinder/files/44185890546.pdf In PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/74dj353jephamm5v74q7ac5ddk/85984118929.pdfIn PDF document text
    • http://laserinnsbruck.com/static/23285424571.pdfIn PDF document text
    • https://odlingfamily.com/userfiles/file/wilopofeleguxuwal.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/gewuvejepagevezuwigima.pdfIn PDF document text
    • http://driscollandgibson.com/images/edit_images/file/memufopalanusolebase.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/433857978.pdfIn PDF document text
    • https://optimustelecoms.com/ckfinder/userfiles/files/83938432627.pdfIn PDF document text
    • https://dom4m.lv/userfiles/files/30927603647.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/waledase.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/semujezogirazakezonogofit.pdfIn PDF document text
    • http://katachizu.com/img/news/files/vunexulazoji.pdfIn PDF document text
    • http://firegallery.ru/img/upload/lezevomezivajutemaleb.pdfIn PDF document text
    • https://fiscalonline.ro/app/webroot/files/userfiles/files/69365837051.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/33559312729.pdfIn PDF document text
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/xemofej.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/90447713503.pdfIn PDF document text
    • http://agilesolutions.in/uploads/muxiwoxataxanutu.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/lozudodalesozemaze.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/tuzujesisojuxepime.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/61711718327.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/14557729264.pdfIn PDF document text
    • http://trustarshida.co/cache/fck_files/file/43361283794.pdfIn PDF document text
    • http://coyada.com/up_images/up_images/tejusarekidesopuxediken.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=what+is+the+collective+noun+for+a+group+of+singersPDF 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_off0000be0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE0D 10916 bytes
SHA-256: e1e0d6cc43479bf8eb3265d65fb7037d1c70a2acba3817def644d1030413797a
font_01_sfnt_off0000d751.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD751 16012 bytes
SHA-256: 704ef2b1b8ad36c6ae3546b0280b512e09b0ac816c6b5691690d0e708453035e
font_02_sfnt_off0001004d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1004D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1