Malicious PDF — malware analysis report

Static analysis result for SHA-256 835b7dbe03d0bbb2…

MALICIOUS

PDF

70.1 KB Created: 2021-09-26 22:04:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 2dcb83951edc84a228d5a55cf7dae838 SHA-1: 6b7e56862d855697b5fcb65abab4fc74ebaa5073 SHA-256: 835b7dbe03d0bbb25f79a169d89ef0728f26d06a397e8489ab386dee648021f2
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. The PDF also functions as a link farm, with numerous external URLs pointing to other PDF files, suggesting a multi-stage infection or phishing campaign. The presence of JavaScript indicates an attempt to execute code, likely to download further payloads or redirect the user to malicious sites.

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://hiddencliff.kr/FileData/ckfinder/files/20210914_13DA3D265B64E544.pdf In PDF document text
    • http://reopen911.info/media/file/jewotame.pdfIn PDF document text
    • http://garage-fuji.jp/js/upload/files/54773786957.pdfIn PDF document text
    • https://muahohangnhat.com/app/webroot/uploads/files/57717751670.pdfIn PDF document text
    • https://relans-nn.ru/images/docs/file/32610870432.pdfIn PDF document text
    • http://sllight.ru/design/img/upload/file/62651222533.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/32811250204.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/00pooijka9gq5n0vht3ictqrnq/nejapiwikejepina.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/godukevanavutuzes.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/79000022551.pdfIn PDF document text
    • http://jcnjl.com/userfiles/files/82990117866.pdfIn PDF document text
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/70895846217.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/jizikutiwujodaxale.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/fitonunijobovip.pdfIn PDF document text
    • http://clainvest.pl/userfiles/file/nizetumimug.pdfIn PDF document text
    • http://akcompany.vn/uploads/userfiles/file/10550513376.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/nokoworelakutamuvaza.pdfIn PDF document text
    • http://malbreil.com/userfiles/file/49118012854.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/wenegopamonetodibife.pdfIn PDF document text
    • https://anbuadidravidarmatrimony.com/ckfinder/userfiles/files/52319752917.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614aec6b012c1---79265230078.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=can+you+update+an+old+android+phonePDF 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_off0000ad43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD43 17808 bytes
SHA-256: 1a486fb3b281188ef24254eb09c76a18eb9b35bc74589487667bafbc45129966
font_01_sfnt_off0000dab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f2c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C8 10568 bytes
SHA-256: 9ba8167c1b13408a7f56bd509c90116d05823fe4542ad7fb5d7d87530b3fb44e

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