Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8b38403fa66eb62…

MALICIOUS

PDF

79.6 KB Created: 2021-03-21 05:33:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 4d6a136e03a1c554120e80fc012a4ec9 SHA-1: 78b05e573554fa1ff45e2781ae7dd5a7a7b90e4c SHA-256: c8b38403fa66eb627806cadc6bbaca1ee435fcf999944f189f2a9a6356772c7f
126 Risk Score

Malware Insights

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

The PDF contains numerous external URIs, many hosted on disposable domains, and is flagged by ML classifiers and ClamAV as malicious. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a tactic to obscure malicious links within a large number of seemingly legitimate ones. The primary malicious URL identified is vilenefex.ru, which is likely used to host a phishing page or a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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/strik?utm_term=samsung+q7+series+65+inch PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4369498/normal_6006c88f9425c.pdfIn PDF document text
    • http://rowexusaje.mypressonline.com/bestselling_novels.pdfIn PDF document text
    • http://betijeduw.getenjoyment.net/internal_combustion_engine_ap_world_history.pdfIn PDF document text
    • http://siwivelijutore.medianewsonline.com/43924777541.pdfIn PDF document text
    • https://cdn.sqhk.co/zuxosutuku/fkhh5zX/vufalibikegili.pdfIn PDF document text
    • https://cdn.sqhk.co/gosukutusu/6hcjda2/horde_defence_mod_apk_download.pdfIn PDF document text
    • https://bufogepuvuzi.weebly.com/uploads/1/3/1/3/131381066/vunulij.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375708/normal_604f35d60c911.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4496824/normal_5fc8ced459529.pdfIn PDF document text
    • https://sukodijam.weebly.com/uploads/1/3/4/5/134516983/fewelaxezo_nefimulevudo_pigoneno_nimesojetebezez.pdfIn PDF document text
    • https://cdn.sqhk.co/titukopano/5Lwhdhf/descargar_pixel_car_racing_hack.pdfIn PDF document text
    • https://jarivilil.weebly.com/uploads/1/3/4/0/134012847/zitasivugi-fudipo-besuw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387232/normal_60522c6f8bff4.pdfIn PDF document text
    • https://jedawakebikota.weebly.com/uploads/1/3/4/7/134715316/7405337.pdfIn PDF document text
    • http://bivoxuwod.iblogger.org/fejedomuginuzaso.pdfIn PDF document text
    • http://rusidaf.22web.org/algorithms_for_optimization_download.pdfIn PDF document text
    • http://mazikopipovix.mywebcommunity.org/dia_de_la_madre_mexico_fecha.pdfIn PDF document text
    • https://cdn.sqhk.co/zezinojox/jNVUhWQ/66094769429.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://madepug.rf.gd/xemibogogalivudubetuzebi.pdfIn PDF document text
    • http://soripijadob.rf.gd/rovemoz.pdfIn PDF document text
    • https://dfabac9c-3a78-4d86-b112-ccf1750024e9.filesusr.com/ugd/b46e2f_286df00bd4b642c88e773923a920f286.pdf?index=trueIn PDF document text
    • https://627f215e-41ba-4aa4-9906-5f9f9d117739.filesusr.com/ugd/8ab72e_e4f5691fe1ad47c69128a9301594567e.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
    • 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_off0000dd0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0D 5768 bytes
SHA-256: b2e2aa529c8a37ded24c2200e7c12d190cead123595ca2947223dd0b13fe1a7b
font_01_sfnt_off0000f090.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF090 12100 bytes
SHA-256: 96500532b729cd3ecbfd273a8aa471c297e7aecb2fa2f653665c94f4ef41be79
font_02_sfnt_off000119ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119EC 16272 bytes
SHA-256: a7b1e01542dab829d2ba5dd7846da79335ded9f65a948c274aeb683100f5fd08