Malicious PDF — malware analysis report

Static analysis result for SHA-256 4266fb7edd1405ad…

MALICIOUS

PDF

82.3 KB Created: 2021-09-09 01:30:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c83fb4ffbc52d36e036971af0f4da0a0 SHA-1: 126202cd56cd02eba031ca6a02a4dbf0a89f1c88 SHA-256: 4266fb7edd1405ad1d56e0f745593ae890a5c8ee2c91cd5e1af116370a27a90f
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains, suggesting a link farm or redirection mechanism. The primary purpose appears to be directing users to potentially malicious external sites, indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://rld-carbon.com/file/11956082288.pdf In PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/ludejisanimutapejo.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4deed19e6---15881532445.pdfIn PDF document text
    • http://xn--80aaaaadfwa5aftjhxrkcrg8iwc.xn--p1ai/pict/file/30744543124.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/35140771569.pdfIn PDF document text
    • http://medical-1669.com/userfiles/files/21729031029.pdfIn PDF document text
    • http://phantasos.org/userfiles/file/seridajudepi.pdfIn PDF document text
    • https://marmetal.cevhertemizlik.com/userfiles/files/49217753427.pdfIn PDF document text
    • https://postelezmasivu-praha.cz/ckfinder/userfiles/files/nupuvibif.pdfIn PDF document text
    • https://i-chat.tw/js/ckfinder/userfiles/files/61633117650.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/zubisu.pdfIn PDF document text
    • https://shiokuda2.com/contents/files/zititotabowadetiw.pdfIn PDF document text
    • http://lixupeng.com/uploads/files/10388736471.pdfIn PDF document text
    • http://ecoevopublisher.com/files/upfiles/file/lanim.pdfIn PDF document text
    • http://myappartement.de/web/editor/files/44946216715.pdfIn PDF document text
    • http://sonnenheizung.ch/fckeditor/editor/images/file/zoxolobeza.pdfIn PDF document text
    • http://thcsnguyenvanhuyen.hoaiduc.edu.vn/ckfinder/userfiles/files/romidukesaruve.pdfIn PDF document text
    • http://mathcountsoutreach.org/userfiles/file/47474689586.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/7660618883.pdfIn PDF document text
    • http://lagerunda.it/public/upload/file/205865960.pdfIn PDF document text
    • http://rockefellersgold.hu/editor_up/52865061492.pdfIn PDF document text
    • http://fabtur.ru/upload/files/58833303496.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/bogosebovafonavawifup.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161362bd86531b---resoxolegeg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=amapiano+beat+maker+pro+apkPDF link annotation
    • http://s250801404.onlinehome.fr/img/uploaded/file/76020857438.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_off0000debb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CD 17228 bytes
SHA-256: a28d8c412327fc395a90b3719dee8a8ef362310f1f017327e6ec0c24a29adbe5
font_02_sfnt_off000123dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123DC 10412 bytes
SHA-256: bf38b8fc2bf94ef9b66e16a0a1e968c08bbeef516f575c195f736b97882cd2c7