Malicious PDF — malware analysis report

Static analysis result for SHA-256 b53bc401cb84937d…

MALICIOUS

PDF

75.0 KB Created: 2021-09-21 14:04:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6c30de2e48c2941bd0967619611a5c51 SHA-1: a3e3a243df3b98997126127d8e00e1fae8dbde93 SHA-256: b53bc401cb84937da2d303aabeae143b1a737972108b1535fe513ea4e7c19b16
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is often used to redirect users to malicious websites or download further payloads. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous extracted URLs suggest a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://pes.edu.mn/ckfinder/userfiles/files/milula.pdf In PDF document text
    • http://mygiftltd.com/userfiles/file/49769933493.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/55662377620.pdfIn PDF document text
    • http://hindel-relax.ch/ckfinder/userfiles/files/34917967477.pdfIn PDF document text
    • http://cuanhuadanang.vn/uploads/image/files/wumorudibixi.pdfIn PDF document text
    • https://octvads.site/js/ckfinder/userfiles/files/49525795975.pdfIn PDF document text
    • https://haltia.mx/sii/ckfinder/userfiles/files/96133040686.pdfIn PDF document text
    • http://www.icf-plant.com/files/file/xepalemikamajigopadu.pdfIn PDF document text
    • http://wdnederland.nl/file/41841275964.pdfIn PDF document text
    • http://alfatreyd-mebel.ru/archive/images/file/liwiro.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/79697212251.pdfIn PDF document text
    • https://kawanmto.net/contents/files/liletodikiwegazapituneden.pdfIn PDF document text
    • https://purefeeling8.com/data/file/59531398677.pdfIn PDF document text
    • http://tbvshungviet.com/upload/files/wotazabulotijuwatu.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/5528816835.pdfIn PDF document text
    • http://labotinnghia.com/img/files/54375392850.pdfIn PDF document text
    • http://elitakhealing.com/ckfinder/userfiles/files/8522156394.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614780138e612---57388836343.pdfIn PDF document text
    • https://chung-pei.com/userfiles/file/35642882292.pdfIn PDF document text
    • https://korankertas.com/contents/files/dufebomaxuwor.pdfIn PDF document text
    • http://budropol.de/Upload/file/33997248025.pdfIn PDF document text
    • https://texasbordervolunteers.org/userfiles/file/wigoxikadigogut.pdfIn PDF document text
    • http://ksklinika.ru/ckfinder/userfiles/files/dapaperug.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/89176249802.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/nafusefizudu.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce1ed2f72b---7081669020.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=fifa+21+psp+iso+downloadPDF 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_off0000c319.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC319 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB2B 16812 bytes
SHA-256: 655501eaeb854bd6e72834cb3a344063b3a508f7b42e32b44a80a1106cccbe52
font_02_sfnt_off000106a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106A7 10396 bytes
SHA-256: 821de6e6aa7a1004dd8276a44840f271942005d115fd30d20a4fbde70f3452ec