Malicious PDF — malware analysis report

Static analysis result for SHA-256 83138ba9ac6f5dcd…

MALICIOUS

PDF

86.5 KB Created: 2021-02-01 01:59:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 57f6b2cad515ceb70e133daa635bcea9 SHA-1: 9ba4677ef718a75fb87f9680933de25116a40e1a SHA-256: 83138ba9ac6f5dcd7800ad8f450499c5cef948f35f8c016a05baa0d5745550a1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous links, many pointing to disposable domains, suggesting it functions as a link farm or phishing lure. The primary IOC is the external URI pointing to a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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/123?utm_term=faded+copy+of+riptide PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4367919/normal_600bffd2a5446.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413240/normal_5ffd758fde7a7.pdfIn PDF document text
    • https://tusagenitig.weebly.com/uploads/1/3/1/4/131452801/jodogukon.pdfIn PDF document text
    • https://bijazebis.weebly.com/uploads/1/3/1/3/131382141/fuvomigiwiz_venufiwutem.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4380088/normal_5ff1d2161429e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368989/normal_5fc5837f3e250.pdfIn PDF document text
    • http://xujukega.66ghz.com/divefobanom.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407793/normal_5fd2271a1ce25.pdfIn PDF document text
    • https://waragorejitise.weebly.com/uploads/1/3/0/8/130813548/fuvesi_suxegerinabotuk_mijiboku.pdfIn PDF document text
    • https://nelemiken.weebly.com/uploads/1/3/4/7/134704654/xupamizagixi_nupuva_falemibug_wiboviw.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bokakemipik.epizy.com/cbt_full_form_in_fssai_exam.pdfIn PDF document text
    • http://lokimutopilar.epizy.com/55889737805.pdfIn PDF document text
    • http://dujisuga.epizy.com/bot_binary_android_gratis.pdfIn PDF document text
    • http://renureva.epizy.com/sawop.pdfIn PDF document text
    • http://zapofekeba.rf.gd/panuger.pdfIn PDF document text
    • http://nezenomawaza.epizy.com/fafofajojud.pdfIn PDF document text
    • https://s3.amazonaws.com/rebomedug/4k_video_converter_free.pdfIn PDF document text
    • http://favagapararo.epizy.com/vuradol.pdfIn PDF document text
    • http://bumufemukelogik.epizy.com/antalyaspor_formas_2018.pdfIn PDF document text
    • http://xinudigiwuwa.epizy.com/29393392848.pdfIn PDF document text
    • https://s3.amazonaws.com/titugome/40740882392.pdfIn PDF document text
    • https://s3.amazonaws.com/savifin/microsoft_authenticator_for_windows_10.pdfIn PDF document text
    • https://s3.amazonaws.com/jagux/pokonapena.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_off0001014b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1014B 4996 bytes
SHA-256: 4a9e6fcb2c8349cb303e8502407fabfb1c0a13c91d6ddace39e7ebf70f55fc80
font_01_sfnt_off0001126a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1126A 10772 bytes
SHA-256: cd956af4cfc770a8a517994f92501b7cfa63f7e121eacb9aa9b05e2e909fcd40
font_02_sfnt_off00013753.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13753 16092 bytes
SHA-256: 39b2f4b99ee08965fd4836f89f628a00cde8346cb181131bba0308e80db8fb67