Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d2ea9c26ff883b6…

MALICIOUS

PDF

77.2 KB Created: 2021-09-22 09:46:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c4ba54451f48949a7fbbf4b830f246cf SHA-1: 8d9fb4b7a7949e10fd48b2281801ca68a7c308ca SHA-256: 5d2ea9c26ff883b609d4ae45a3c3ca457801f48d6669f9e5350b7a2b6aec8aae
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting vulnerabilities or delivering malicious content. The PDF also exhibits characteristics of a link farm, with numerous external URIs pointing to various PDF files, suggesting an attempt to distribute further malware or engage in phishing. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://flooroverstock.com/admin/userfiles/file/wazufujizusozevas.pdf In PDF document text
    • http://regalmotors-jp.com/js/upload/files/6726435826.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210910_6391D7593E679A33.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/malajat.pdfIn PDF document text
    • https://cortopolis.ar/userfiles/file/kakes.pdfIn PDF document text
    • https://mar3ol.com/Files/files/kevaxofov.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/179263212.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/23158579086.pdfIn PDF document text
    • https://clubslotalmatriche.com/calcas/file/lelagozitu.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/kevitesaginozup.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/xudugusu.pdfIn PDF document text
    • http://paroissedementon.fr/upload/files/vojututoxadaloxafilivama.pdfIn PDF document text
    • http://oecschool.com/userfiles/file/kolalefe.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7ff0ade21---tebarigagofiridorododujub.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/boviposef.pdfIn PDF document text
    • http://lilcash.com/ckfinder/userfiles/files/40856890939.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/jutubelunixejamopexu.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/nawogaxuv.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9fa8084a4---36772288277.pdfIn PDF document text
    • https://nbcmedia.vn/ckfinder/userfiles/files/gijizurupowipupugonuwem.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/27557925404.pdfIn PDF document text
    • http://parateam.cz/file/nupokisufi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=percy+jackson+2+book+pdfPDF 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_off0000c786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC786 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF9D 10976 bytes
SHA-256: d5034c9fa40d90a3f11ef75a616d74e1f2165f9f69b6310c2895dbb048a7f6e9
font_02_sfnt_off0000f918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF918 17932 bytes
SHA-256: 52693b8672fed7cf6bc870fc96a707382b9748ce38ab6915c6597b0d52c9121f