Malicious PDF — malware analysis report

Static analysis result for SHA-256 6bc243f9e7fc5783…

MALICIOUS

PDF

78.0 KB Created: 2021-03-25 06:16:52 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 75255e46bdec2b83e412ba456cc26c6b SHA-1: 511d67ccf60864737c744ec31f092cb8b845a84b SHA-256: 6bc243f9e7fc57837daebe0b1f3bd9952594b12e1fd868b278c3d9af06212d05
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious content. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm designed to redirect users to potentially malicious sites. The presence of external URIs and the overall structure strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://zajinet.ru/wix?keyword=irulu+tablet+case
    • http://freshmind.net/26284016678e9s1l.pdf
    • https://cdn.sqhk.co/tejilunuf/iaoidO5/90613854650.pdf
    • https://cdn-cms.f-static.net/uploads/4489599/normal_601db5493650c.pdf
    • http://policyhelpcenter.com/edema_cerebral_sintomasm7vt0.pdf
    • https://cdn.sqhk.co/walamalesumi/dS8Giez/soteworodifokowurepawenev.pdf
    • https://cdn-cms.f-static.net/uploads/4450884/normal_604ce61adaaf9.pdf
    • https://cdn.sqhk.co/kuwusemob/qCyRcJP/fdic_call_report_glossary.pdf
    • http://imedo.ru/pikaganopubetet31co.pdf
    • http://texoraw.sportsontheweb.net/asal_muasal_pelukan_candra_malik.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://xepatodop.onlinewebshop.net/greek_mythology_reviewer.pdf
    • https://88749095-6fd7-453f-8e8a-15b48fe47dd1.filesusr.com/ugd/e4d7df_28835ee6f0ab4e6eaa4be102f2f79376.pdf?index=true
    • https://203aa715-7352-46b1-b16b-5d0aeeaa27a2.filesusr.com/ugd/0582e0_01f603ee8ac2423ab6dcb29421875b71.pdf?index=true
    • https://uploads.strikinglycdn.com/files/fa69f192-a2f5-4e65-8b14-e75962007073/43246208058.pdf
    • https://uploads.strikinglycdn.com/files/9348ae18-47b7-4761-8f8f-e30f0f413c0a/99410414531.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f448.bin
b02f1965dc777e28c4573f33268be7c3f6483b27d0bedb73df7ac3469e77dbe9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF448 4872 bytes
font_01_sfnt_off000104da.bin
a31010a97ce2e249db66f3e90d2087f9d49777718b271093ffe6448e020840eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x104DA 11184 bytes