Malicious PDF — malware analysis report

Static analysis result for SHA-256 4574556d3e83fd9c…

MALICIOUS

PDF

77.2 KB Created: 2021-04-28 03:33:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2ec7676eb6d852d338075ff9c4aa6709 SHA-1: 7a2c4d961784cebf1796354f3505508b59995996 SHA-256: 4574556d3e83fd9c892234c9172bf6659b99a63651bddf0cd2763b6f98d7e4e6
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and embedded URIs are indicative of a spearphishing attachment designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://kuzutuzo.ru/strik?utm_term=brother+hl-l2360dw+connect+to+wifi
    • https://cdn-cms.f-static.net/uploads/4381737/normal_601f7184cbdb8.pdf
    • https://static.s123-cdn-static.com/uploads/4377662/normal_60025b7ef1fa7.pdf
    • https://gemunokixelu.weebly.com/uploads/1/3/6/0/136095878/kidipafuvetomaveji.pdf
    • https://cdn-cms.f-static.net/uploads/4448539/normal_603e3bfd3f028.pdf
    • https://bofakodejo.weebly.com/uploads/1/3/4/2/134265658/jawinoditen-ximadez.pdf
    • https://pinozawekik.weebly.com/uploads/1/3/4/5/134589254/dejibodu.pdf
    • https://loseseseveru.weebly.com/uploads/1/3/0/8/130813975/828628a4fd.pdf
    • http://moxokivotalunuz.iblogger.org/misplaced_modifiers_quiz_with_answers.pdf
    • https://cdn-cms.f-static.net/uploads/4446398/normal_604cd160dd26e.pdf
    • https://rofinodaki.weebly.com/uploads/1/3/4/7/134721453/sogugixez_xetaruzidina_livixubeges.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/b6b97cd7-7d43-4e70-98f2-b8840b87ba52/xamukapalumuxolaxiz.pdf
    • https://s3.amazonaws.com/defujo/template_plan_d_action_ppt.pdf
    • https://b7af6bb9-01eb-4839-ab56-764651de4344.filesusr.com/ugd/2486b5_ebf179bf748e4c68878f078d446f964e.pdf?index=true
    • https://s3.amazonaws.com/novifamigot/punovevidu.pdf
    • https://uploads.strikinglycdn.com/files/9cca0195-34c3-460a-8147-569e1019900c/tadosebuvi.pdf
    • https://6346cca1-8be9-442e-91e0-e35201572fa6.filesusr.com/ugd/a8c077_a359ee4686c94508a41464cb044b005f.pdf?index=true
    • https://uploads.strikinglycdn.com/files/6c45c900-9066-4895-aefc-c92395a8e9e1/88154861455.pdf
    • https://s3.amazonaws.com/lofese/total_coliform_colilert_mpn_enumeration.pdf
    • https://s3.amazonaws.com/pojikovewijeja/nadaforeragevugi.pdf
    • https://s3.amazonaws.com/tonemakopinibem/what_to_wear_to_a_fight_party.pdf
    • https://03df18d0-0a94-4077-8b44-1f3cf8b7c870.filesusr.com/ugd/23a6c3_ffbd7ec7727c477d8ccb0f4f8523d02e.pdf?index=true
    • https://uploads.strikinglycdn.com/files/49612762-1f32-40fc-8a02-90c6b269e4ff/merovingian_looped_fibulae_khan_academy.pdf
    • https://94db4134-5784-44c5-a63d-963e509970fa.filesusr.com/ugd/9c58c5_1f622b7747124d528d0dd99eeb128af4.pdf?index=true
    • http://zerodawoti.rf.gd/jofateganifazawinolawe.pdf
    • https://1c92f6d8-19eb-429c-9239-1cf6be91372f.filesusr.com/ugd/cc1a03_72aa7a7e486c4312bcab7e65810c899e.pdf?index=true
    • https://uploads.strikinglycdn.com/files/364698ff-743f-4bce-9c9a-99aaaf085a40/wisanovidoxevozujibogegom.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_off0000f121.bin
399e42680f9f21610fc3a5ee66bb894553f8820e4af97feb8e86e6fe38e58988
pdf-font-stream PDF embedded font (sfnt) at offset 0xF121 5488 bytes
font_01_sfnt_off000103ee.bin
d7e2d5664ac0d0b2ca70fee4130486ef96d6529b61c52d8136b976393af9a555
pdf-font-stream PDF embedded font (sfnt) at offset 0x103EE 10328 bytes