Malicious PDF — malware analysis report

Static analysis result for SHA-256 b373ecdc061d3ac9…

MALICIOUS

PDF

80.8 KB Created: 2021-03-20 21:21:25 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 1823829345e52a75cb4e3e3d715ca247 SHA-1: 5ee0624ac06298f5d51ca3bc3bace86fb0458ddf SHA-256: b373ecdc061d3ac95a7958b4a449a1f2cf7fbf332787ffbece31815e58b1335a
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, with one specifically identified as an external URI pointing to 'https://vilenefex.ru/award?keyword=canon+90d+user+manual+pdf'. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is designed as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. No scripts were extracted, but the overall structure and embedded URLs point towards a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 5

  • 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.
  • 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://vilenefex.ru/award?keyword=canon+90d+user+manual+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4427295/normal_6039e4cf96b13.pdfIn PDF document text
    • http://worldhold.online/raruxebuzulu55ysh.pdfIn PDF document text
    • https://cdn.sqhk.co/lanumakefu/eidhgtK/13254359194.pdfIn PDF document text
    • https://cdn.sqhk.co/fejisunez/F2sGjbJ/swatch_definition_synonym.pdfIn PDF document text
    • https://cdn.sqhk.co/ranilabar/3hiifvM/bootstrap_templates_with_login_and_registration_form.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378628/normal_60534fd2ab1b8.pdfIn PDF document text
    • http://gallery-shop.site/7295115059701ah3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393346/normal_60063a6530c0f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415770/normal_6008b5dc79f50.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368467/normal_604174590461c.pdfIn PDF document text
    • http://verification-help.com/nursing_drug_handbook_free_download8anix.pdfIn PDF document text
    • https://cdn.sqhk.co/bebumila/pOKhbjb/zigilixelu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404740/normal_60062e145c8dc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4386851/normal_5ff535522cea0.pdfIn PDF document text
    • http://avto-trokot.xyz/12898095815zasq2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447273/normal_5fdccf01bf807.pdfIn PDF document text
    • https://cdn.sqhk.co/nufesewepi/hjKoTic/free_tv_apps_for_iphone_2019.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420939/normal_5feaffe32d63c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/5d8805ac-b28c-4e3d-9346-0b3f5169687d/wigasidifamo.pdfIn PDF document text
    • https://s3.amazonaws.com/jezaxojipevu/have_got_questions_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8fa1f44b-518e-4e4e-b75d-11e4b1b8b62a/422708163.pdfIn PDF document text
    • https://s3.amazonaws.com/goneduzum/citizenship_test_questions_and_answers_in_punjabi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/70a708bd-eadf-44ca-8312-fbfc1513e583/best_daily_english_words_app.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0cf81519-d0ba-428f-8e47-942058130463/good_machine_learning_books_reddit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/310cd5ab-c40f-4d79-ad49-afa47eec731a/77681265833.pdfIn PDF document text
    • https://s3.amazonaws.com/nisiwanolom/dimug.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_off0000fdf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDF3 5388 bytes
SHA-256: fa741adc95ab5c1158ed63c94ae93e30b906cd22c709986d743819eac2ac4f72
font_01_sfnt_off00011026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11026 10916 bytes
SHA-256: fdfd402d8c1373544a2aa65571fe34e30b7be9e8a90bbfd9ec2cbef2db2711c8