Malicious PDF — malware analysis report

Static analysis result for SHA-256 c426930c1a137c8c…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 14:11:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 82b8a5f4937584874fd3744086d82a58 SHA-1: d3639e5554beaa999cf80d5cf36f20b53221ec64 SHA-256: c426930c1a137c8c3bd1f0cd218c5fcc7b29d00ceb367da37101d074fa717921
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains numerous embedded URLs, many pointing to suspicious domains, and a heuristic identified it as a link farm on disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and heuristic firings indicate a malicious intent to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://formel1vermietung.de/userfiles/file/80483818954.pdf In PDF document text
    • http://grapes4u.ca/sites/all/sites/grapes4u.ca/files/wojadowililodelupus.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/pemitukibi.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/fodemekutatuponuvo.pdfIn PDF document text
    • http://mtsp.by/userfiles/files/jawojobemut.pdfIn PDF document text
    • http://888chji.com/userfiles/files/76500651780.pdfIn PDF document text
    • http://autoscuolapezzano.it/userfiles/files/25954421062.pdfIn PDF document text
    • http://sanyosushiglendora.com/uploads/files/zunexogukozorirakum.pdfIn PDF document text
    • http://adice-area.com/pictures/files/41019033744.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210909012939.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/bodotosunotulugoxabux.pdfIn PDF document text
    • https://laplacedesstores.com/upload/file/ponibeb.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/mugorugu.pdfIn PDF document text
    • http://finance-bulldog.cz/UserFiles/File/lijozezogosinikesavo.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/8172351830.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/60148470140.pdfIn PDF document text
    • https://diphong.com/uploads/wuwebepewopudunoluzuxukub.pdfIn PDF document text
    • http://pc580.cn/upload_fck/file/2021-9-1/20210901095250673453.pdfIn PDF document text
    • http://simonide.org/userfiles/file/bujizifisibawo.pdfIn PDF document text
    • https://drishtinetcom.in/FCKeditor/file/mitobeke.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16130689d806f0---12793247492.pdfIn PDF document text
    • http://dispensapertutti.com/userfiles/files/bukipaba.pdfIn PDF document text
    • https://ibshospitals.com/userfiles/file/legavumolapoja.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+mirror+android+screen+to+macPDF 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_off0000d7ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF000 19268 bytes
SHA-256: 9a7cfc6a1e82d03e7e6b0e05870b066f1ac95fae63a27b7bbe926cced59201f0
font_02_sfnt_off000122d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122D5 10560 bytes
SHA-256: b78e359eff224dd47eacdafb8569c83623de0433e2d319bbc18330c0b1008d3e