Malicious PDF — malware analysis report

Static analysis result for SHA-256 400e4539a0b024d6…

MALICIOUS

PDF

83.8 KB Created: 2021-09-19 03:11:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 44b3493ec8da55c010ca2e9b55c926e5 SHA-1: b1ad11e8230151fd10da1211dcab99f4664761b0 SHA-256: 400e4539a0b024d6580dfe98dc160a23732bf5e64fccf0bc3141fc169acabea6
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript and a large number of external URIs, many of which point to disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The embedded JavaScript, while not directly executed in this static analysis, is a common vector for further exploitation in PDF files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://smidgel.ru/uplcv?utm_term=subject+verb+agreement+exercises+for+class+6+pdf PDF link annotation
    • https://piauiaqui.com/ckfinder/files/96819222586.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/53274673341.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/21837671750.pdfIn PDF document text
    • http://parvazyab.net/basefile/api203/files/xazeresomilukogojijaje.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/45414523168.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/16224552691.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/sapolisozomujiwexajipobit.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/xokonev.pdfIn PDF document text
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/35679830124.pdfIn PDF document text
    • https://mayphotocopydogia.com/upload/files/xuvujutelifopobot.pdfIn PDF document text
    • http://fireprovietnam.net/luutru/files/18492100837.pdfIn PDF document text
    • http://findingthegrey.com/userfiles/file/10932677364.pdfIn PDF document text
    • http://ordineveterinarireggioemilia.it/userfiles/files/gijijibalivof.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/2e7b5607da0c4fe04a60c442160dadc3/tojubukakisimodomije.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/taziw.pdfIn PDF document text
    • http://josquin-capella.de/download/20182696079.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/bevabebinew.pdfIn PDF document text
    • http://skoleniridicu-online.eu/ckfinder/userfiles/files/77294761677.pdfIn PDF document text
    • https://marblobaths.ph/app/webroot/img/files/10104929094.pdfIn PDF document text
    • http://ximangsongthao.com/app/webroot/uploads/files/37510792459.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145e68f74df9---gevojo.pdfIn PDF document text
    • http://optikametuje.cz/userfiles/file/5819632570.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/legan.pdfIn PDF document text
    • http://tonyprins.nl/images/uploads/file/9834185208.pdfIn PDF document text
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/45134341126.pdfIn PDF document text
    • 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_off0000dda1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA1 11744 bytes
SHA-256: 472d18c0a19e236c6430ad78f540c9a4b07f49145a7c10585131298eb84cc72f
font_01_sfnt_off0000f942.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF942 18520 bytes
SHA-256: 9b57969fb5a3e4af7db74517b739a1c77a132fdc9f0d612795dbcd1a62b4d4f8
font_02_sfnt_off000128f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1