Malicious PDF — malware analysis report

Static analysis result for SHA-256 9434c2e0f179073e…

MALICIOUS

PDF

72.5 KB Created: 2021-09-24 13:22:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d2eb16851e1d103b6d9739bdafc8ee0e SHA-1: 1bcd57debe03ece5c1955370183b4813d60e015e SHA-256: 9434c2e0f179073e9699b31d3154fa9543fe634bf13292c38441fb9ec161a323
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with a critical heuristic firing for PDF_SEO_DISPOSABLE_LINK_FARM. It contains embedded JavaScript, indicating an attempt to execute code within the PDF viewer. The numerous external URLs, many pointing to PDF files on potentially disposable domains, suggest a phishing or redirection scheme to deliver further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.
  • 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 https://bedandbreakfastchia.it/userfiles/file/dozasu.pdf In PDF document text
    • http://www.leads-bd.org/app/webroot/js/ckfinder/userfiles/files/xozuko.pdfIn PDF document text
    • http://logo4you.dk/userfiles/file/wefolekojesedomabakaduboj.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/f8c40447ac36568b9c5a422f5fb67c0b/dexumijipana.pdfIn PDF document text
    • http://daisin1977.com/js/upload/files/zopakozatesizekerarot.pdfIn PDF document text
    • http://airsoft1.ro/files/file/23617284504.pdfIn PDF document text
    • https://stockbauer.hu/uploads/file/74786110593.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210913213450.pdfIn PDF document text
    • http://jszl-rolls.com/filespath/files/20210920011201.pdfIn PDF document text
    • http://profstil.az/userfiles/file/pugatejadamavirudiso.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/womotuzob.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/48510644234.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/hvq69t5e33dt4pkm6aiej2vpea/61798043118.pdfIn PDF document text
    • http://cermak-expo.cz/data/files/file/kiwetoxugomomisalijukami.pdfIn PDF document text
    • http://exim5.hu/_user/file/79466620522.pdfIn PDF document text
    • http://zhuoer.ltd/userfiles/file/98985251176.pdfIn PDF document text
    • http://rc-modeller.se/images/file///32652194416.pdfIn PDF document text
    • http://advertisingreports.info/assets/ckfinder/core/connector/php/uploads/files/resibezuvodetusiridig.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/3652716402.pdfIn PDF document text
    • https://pulsekb.ru/admin/ckfinder/userfiles/files/duliponavefimiza.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/224055480.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/zukirekotukekunomages.pdfIn PDF document text
    • http://hexindechem.com/upload/files/99345642911.pdfIn PDF document text
    • http://finalstage.biz/js/upload/files/vapuxufobuwewunifemav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=android+pdf+to+bitmapPDF 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_off0000b515.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB515 18944 bytes
SHA-256: d480c69f69db29c29f3d52d1582db81b74f71bb2cd30368cd213f80e01b8cefd
font_01_sfnt_off0000e4fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD11 10436 bytes
SHA-256: 7fba421b1e1352ce4cf9bb986417504338870e014f0d6465c370417551a23921