Malicious PDF — malware analysis report

Static analysis result for SHA-256 b57b3ca5df20cb28…

MALICIOUS

PDF

79.7 KB Created: 2021-09-19 01:12:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 810b23279cb2a0667f54669a5634741f SHA-1: 3a046d6b2d9c8c80f0126b921d6cd9880d366892 SHA-256: b57b3ca5df20cb2847c1722cc0a3cc0e6edd4dcb0117c5f8721aead9aa0ff213
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for malicious PDFs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a large number of external links hosted on disposable domains, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 https://ketchas.ru/uplcv?utm_term=miui+12+for+mi+8+pro PDF link annotation
    • https://lorus.rs/files/javirijilozanogijir.pdfIn PDF document text
    • https://emotionalgift.com/ckfinder/userfiles/files/80879132185.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/82272880961.pdfIn PDF document text
    • http://mobiliteit.nu/files/31776460194.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/f014c441228d7061f3fd718b9c3800ae/bukiviwusisawu.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/gobaladunujarijinidotak.pdfIn PDF document text
    • http://clarklawtexas.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sixaxadamirafatepiro.pdfIn PDF document text
    • http://3dprofi.net/images/uploads/file/xoweburusuwelurenugedez.pdfIn PDF document text
    • http://allineers.netlovestories.com/upload/files/wokizazo.pdfIn PDF document text
    • https://manage3.realtourvision.com/rtv/ckfinder/userfiles/images/files/lawalugotakurunaderilade.pdfIn PDF document text
    • http://xn--oy2b19v1mb1yi.com/userfiles/file/34183156048.pdfIn PDF document text
    • http://tecniagua.es/uploads/ckfinder/files/25476871077.pdfIn PDF document text
    • http://techcessgroups.com/userfiles/file/35253878562.pdfIn PDF document text
    • http://firmen-bekleidung.at/userfiles/file/19026395682.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/daromitokikopaxezukajof.pdfIn PDF document text
    • http://bakoca.hu/files/file/56489234686.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/dobikufagel.pdfIn PDF document text
    • https://srldirect.com/ckfinder/userfiles/files/51328971217.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/54641491524.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/kafidibatolurise.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/2e8c493c61340133493d160422b1df7c/kereredidufafigezorixaze.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/rulekaripezokikixajir.pdfIn PDF document text
    • https://tonerihned.cz/userfiles/file/60666559866.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_off0000d290.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD290 18364 bytes
SHA-256: 26210a217087b6669f4dff68a830473555d04defab732f14922273759dea2ce8
font_01_sfnt_off00010250.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10250 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A67 10280 bytes
SHA-256: d286ebca9f98b33e0380279e131d1e7b69157095e73b6c2592a85df974ec6523