Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c42fdffbf731af6…

MALICIOUS

PDF

76.5 KB Created: 2021-03-18 14:07:56 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 443c7cf34ef6a14e19b4164eba5a1247 SHA-1: c83768c672aec864723deeeb739bf09ee768d169 SHA-256: 0c42fdffbf731af6d9ab75237032f91d081feeb9d99cf564aa4a3c8e8bf27388
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF file flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous embedded URLs, one of which, 'https://leonvi.ru/aws?utm_term=words+of+wisdom+to+a+new+mother', is directly associated with a heuristic indicating a link farm on disposable hosting. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create malicious PDFs. No scripts were extracted, but the presence of external URIs and the overall malicious classification strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • 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.
  • 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://leonvi.ru/aws?utm_term=words+of+wisdom+to+a+new+mother PDF link annotation
    • http://dietnatur.fun/android_studio_gradle_plugin_updatezlem3.pdfIn PDF document text
    • http://gazagidumow.mygamesonline.org/95988046669.pdfIn PDF document text
    • http://ses-paypal.com/katufojaroriragekitavev741x1.pdfIn PDF document text
    • http://waranijovuv.sportsontheweb.net/uk_bribery_act_guidance.pdfIn PDF document text
    • http://jukekelexoseda.22web.org/does_rainbow_still_make_vacuums.pdfIn PDF document text
    • http://ragadugizidej.22web.org/64867755032.pdfIn PDF document text
    • http://leaninrzpd.site/bane_chronicles_chapters4pewm.pdfIn PDF document text
    • http://helpverifedbadges.com/best_english_grammar_book_free2bhux.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/fodose/android_studio_onclick_in_fragment.pdfIn PDF document text
    • http://vegunag.rf.gd/rejokin.pdfIn PDF document text
    • https://s3.amazonaws.com/zowejunef/46368796430.pdfIn PDF document text
    • http://vonizevugopu.rf.gd/sikopamonajemuvotajizep.pdfIn PDF document text
    • https://s3.amazonaws.com/netinuwa/google_analytics_reporting_api_javascript.pdfIn PDF document text
    • http://duketududolur.rf.gd/92247136829.pdfIn PDF document text
    • http://rusegidi.rf.gd/38631595854.pdfIn PDF document text
    • http://deguwesipi.rf.gd/banting_breakfast_recipes.pdfIn PDF document text
    • http://pavemamixazose.rf.gd/tiniwusevalimabanosap.pdfIn PDF document text
    • http://sejofinudagiji.epizy.com/xunajinesexizewujilap.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eea1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA1 5220 bytes
SHA-256: 2c31b51c6510b5378b625a463134966177f31067c6e4e9d72e36b4776966bc7d
font_01_sfnt_off0001004b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1004B 10344 bytes
SHA-256: d3e1c7534462073fed7d85805f3be194550af38e22c997e4c468a84b165fe8af