Malicious PDF — malware analysis report

Static analysis result for SHA-256 b350a042dacdf376…

MALICIOUS

PDF

75.7 KB Created: 2021-09-16 10:13:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 58a41917c72bb37c06fe59f88f6bb5b3 SHA-1: 1c2ba99ab73c4d487f688734b4daaf021f36d44b SHA-256: b350a042dacdf376d5e34d7b51bcf0326566c56a0fa466dc86de8e664ff646cf
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 contains numerous embedded URLs pointing to various PDF files hosted on different domains, characteristic of a link farm designed to obscure the ultimate destination. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM further supports this, indicating a strategy of using many distinct, potentially disposable hosts. The primary goal appears to be directing users to malicious content through a network of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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://nhaccugiare24h.com/uploads/userfiles/file/visovemimupi.pdf In PDF document text
    • http://fermobkorea.com/userfiles/file/20210914115106.pdfIn PDF document text
    • https://zweefvlieg.net/userfiles/file/21976720771.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161426507d848e---70399107885.pdfIn PDF document text
    • http://qdjshg.com/files/file/xepefuzewuwofiwirozus.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/lgv3h1hm0ugrgi37bn8n0us4fs/doxarosaruj.pdfIn PDF document text
    • https://phm.vn/upload/files/bapegof.pdfIn PDF document text
    • http://rockhousemethod.com/ckfinder/userfiles/files/98205973057.pdfIn PDF document text
    • http://graphicyazd.com/ckfinder/userfiles/files/rijojok.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/kezepurabapinukeporotev.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/56161083470.pdfIn PDF document text
    • https://oncallanatomist.com/ckfinder/userfiles/files/56235496013.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/soxexamekotabedi.pdfIn PDF document text
    • http://rockefellersgold.hu/editor_up/31736911167.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/kedagolabokuruzox.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/zamulitaximawasogediriji.pdfIn PDF document text
    • https://qigoodteam.com/uploads/files/202109131705309266.pdfIn PDF document text
    • http://maradonasalud.com.ar/ckeditor/ckfinder/userfiles/files/zajibejan.pdfIn PDF document text
    • https://argumentua.com/i/file/86155682020.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/76474347555.pdfIn PDF document text
    • http://inggeo.eu/userfiles/files/tixikalabofadidemedut.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/20860009377.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/jodasiganuwakatetuta.pdfIn PDF document text
    • https://bunian-co.com/other_files/File/51432592020.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/28156657848.pdfIn PDF document text
    • http://sanarina.de/ckfinder/userfiles/files/25042598166.pdfIn PDF document text
    • http://skisun.it/userfiles/files/kekexolimawexinowexexupop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=gospel+song+rhett+walker+lyricsPDF 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_off0000c14f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC14F 17536 bytes
SHA-256: dc6e9d29432d8baf3d57a1d6db58148b3bf2ac67b52bc2aa03086fa82cca5c7e
font_01_sfnt_off0000eeed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010704.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10704 10984 bytes
SHA-256: db95148f33b853ade824fd6a836e94e0c8b690c933a95322939fdaa148668ff6