Malicious PDF — malware analysis report

Static analysis result for SHA-256 a41c94aeeada1f37…

MALICIOUS

PDF

76.0 KB Created: 2021-02-17 08:39:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: c7d44ca4d87e0eb463093785d607e907 SHA-1: 5ef10f01e55bea870d4764c0d47129181b45e436 SHA-256: a41c94aeeada1f37514037f5b0faa62dbf48765e03b60787735f26b3749a5313
126 Risk Score

Malware Insights

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

The PDF contains multiple embedded URLs, with a primary suspicious URL pointing to 'jacksth.ru'. Heuristics indicate it's a link farm on disposable hosting, and ClamAV detected it as 'Pdf.Phishing.Trojan'. The document body, though heavily obfuscated, suggests a technical topic ('truncated poisson distribution') to mask the malicious intent. No scripts were extracted, but the PDF structure and URL analysis strongly suggest a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jacksth.ru/strik?utm_term=truncated+poisson+distribution+mean+and+variance PDF link annotation
    • https://cdn.sqhk.co/wixexozesila/ghJihdM/glow_art_drawing_board_amazon.pdfIn PDF document text
    • https://cdn.sqhk.co/pesenexur/diihihi/lego_marvel_superheroes_ps4_cheats_deadpool.pdfIn PDF document text
    • https://cdn.sqhk.co/nojedajoze/K2TjceR/vevikiguvu.pdfIn PDF document text
    • https://funogumoduwe.weebly.com/uploads/1/3/4/3/134309977/kororu.pdfIn PDF document text
    • http://witaseru.iblogger.org/tizob.pdfIn PDF document text
    • https://sididipukiwe.weebly.com/uploads/1/3/1/3/131398020/966331.pdfIn PDF document text
    • http://magicwoolshop.com/arunachalam_movie_tamilgun1yzlw.pdfIn PDF document text
    • https://sofaruxilo.weebly.com/uploads/1/3/5/3/135309187/2114770.pdfIn PDF document text
    • http://jonuzukuforab.iblogger.org/biosecurity_in_poultry_production.pdfIn PDF document text
    • https://sozagigojo.weebly.com/uploads/1/3/1/4/131454883/0598a2e82232.pdfIn PDF document text
    • https://cdn.sqhk.co/ravuviwidi/byihib0/ant_war_movie_in_tamil_free_download.pdfIn PDF document text
    • http://juwapes.22web.org/amma_songs_tamiltunes.pdfIn PDF document text
    • http://coolmag.biz/temusapunanebiviwulevot6s4gc.pdfIn PDF document text
    • https://cdn.sqhk.co/semejegofip/CifY4uG/31028576182.pdfIn PDF document text
    • https://cdn.sqhk.co/busibelifiv/jafNpZH/dugagiredakiruzukuw.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://danofef.rf.gd/anghami_apk_pc.pdfIn PDF document text
    • http://jiditorugap.epizy.com/xugilenudojiwujorovanova.pdfIn PDF document text
    • http://pibusobi.epizy.com/48591089627.pdfIn PDF document text
    • http://lozekav.epizy.com/chickpea_seed_production_manual.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
    • 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_off0000d14c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD14C 5336 bytes
SHA-256: 4154eec4b7a84eb89a92d91b5c5a355b853c229a6f1ab56cd6abc5a202035016
font_01_sfnt_off0000e358.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE358 12792 bytes
SHA-256: 2bd3e78a864de80985507db35ab157e573048217e32289fc54a34ed8cc93178a
font_02_sfnt_off00010d49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D49 16064 bytes
SHA-256: 14bd2f880aa88d290a5069ea199f33b51c7c0b866cb5f393bea19a279cad209a

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