Malicious PDF — malware analysis report

Static analysis result for SHA-256 402b4be42aa46ce6…

MALICIOUS

PDF

118.5 KB Created: 2021-03-14 15:17:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 53310cd5b3a748004028b903a99f4f7b SHA-1: 204a71d13e51896509a0b4816c897c8ac1e72d6c SHA-256: 402b4be42aa46ce6c0c0713fcee01235a8cababae55742b1b0c4700664ab1f85
186 Risk Score

Malware Insights

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

This PDF document contains a large number of external links, many of which point to disposable hosting. The primary URL, https://vilenefex.ru/strik, is likely used to redirect users to a malicious site. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 6

  • 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 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.
  • 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/strik?utm_term=what+fun+things+to+do+with+a+babysitter PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4451757/normal_6022c7c83b37d.pdfIn PDF document text
    • https://cdn.sqhk.co/memenewo/jePwjhS/piano_course_for_beginners.pdfIn PDF document text
    • https://cdn.sqhk.co/lotidonita/cvgdWha/xigenirizoresiroxawoxa.pdfIn PDF document text
    • https://cdn.sqhk.co/lididiregi/hcOjaOP/44817803452.pdfIn PDF document text
    • https://cdn.sqhk.co/wezufunin/eWFZPgh/zomeginirepimafub.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410006/normal_601093f9bc555.pdfIn PDF document text
    • https://cdn.sqhk.co/zaviresodew/ViiTge4/30161703493.pdfIn PDF document text
    • https://cdn.sqhk.co/zimogemage/nKgfKjf/sakadezuwipuda.pdfIn PDF document text
    • https://cdn.sqhk.co/lukulobu/gjEiiTy/equivalent_fractions_colouring_worksheet_ks2.pdfIn PDF document text
    • https://cdn.sqhk.co/rojotuwo/8TU0ijD/telangana_gattu_meeda_chandamama_naa_songs.pdfIn PDF document text
    • https://cdn.sqhk.co/rogokivika/h7iggiA/tolitita.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://557345b1-98c6-442d-b460-9e357c178e5b.filesusr.com/ugd/dfb5f8_033eafc09fa5444fbfd77fa78d913784.pdf?index=trueIn PDF document text
    • https://abee6ad4-cf47-459a-954e-22b9b9bb30ad.filesusr.com/ugd/4bdc6d_2e9cdbcd55a8450d9757f310425d0efd.pdf?index=trueIn PDF document text
    • https://aa3bb5c3-2bd4-4791-9e2a-6e31d5009b04.filesusr.com/ugd/60e703_380a698592754d89ab77ea6e222430ff.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zeworibuzoza/wuwupixufo.pdfIn PDF document text
    • https://4f870d4f-701c-4ec6-bbb3-7277acc5528a.filesusr.com/ugd/fdcb8d_252a561b126e4014a201e60c95b408d9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/rudelazifizuvo/mppsc_assistant_engineer_civil_syllabus.pdfIn PDF document text
    • https://s3.amazonaws.com/webipejonavuv/8462995398.pdfIn PDF document text
    • https://af6bd0e1-9fb2-4c52-b6e5-df6188d17e94.filesusr.com/ugd/771d18_546343e4e6474311aa88092df97e8921.pdf?index=trueIn PDF document text
    • https://9e730ba1-499c-413e-9a09-8a81f8121270.filesusr.com/ugd/0a0016_b16923a254314529872a5dd8f25c557f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tajimipojimo/buffered_vpn_apk.pdfIn PDF document text
    • https://527ed197-5826-4432-9c89-449afa9d705e.filesusr.com/ugd/65ef70_f77b1861708f4f0c85cc18fa5e5022a0.pdf?index=trueIn PDF document text
    • https://0dd0cd87-80d3-4eb5-b9c6-73c43c3a6fca.filesusr.com/ugd/f0b6b3_34dfeece45fc4e75b849186bbccb5f15.pdf?index=trueIn 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_off0001941f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1941F 5484 bytes
SHA-256: b88106f63384c2f9f79b515547e4c2c713496b4b408b91685779c447c4f24a60
font_01_sfnt_off0001a6e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A6E0 11128 bytes
SHA-256: cbbd9f1d01851a5015687e0f1441b38da7629e962dbb3c8bfbcb8f579e2368e2