Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f4decd0c77186c0…

MALICIOUS

PDF

83.3 KB Created: 2021-03-22 16:10:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 5294fbc10e9d35a1aeee4bb802850fb5 SHA-1: c375de88d75d0e10f8be446dfffc4383f2cc7d4b SHA-256: 4f4decd0c77186c036fce606925689f32859ca8a766e6ef4e705d6c2d00011b6
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting services, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. The embedded URLs and the nature of the link farm suggest an attempt to lure users to malicious content or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://jottigo.ru/award?keyword=essentials+of+diagnostic+microbiology+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4494140/normal_6041a8fd2ace5.pdfIn PDF document text
    • https://rupilobeva.weebly.com/uploads/1/3/0/7/130775598/984360.pdfIn PDF document text
    • http://sunshop.pro/arkadelphia_arkansas_mapf7exp.pdfIn PDF document text
    • https://lokugejepotag.weebly.com/uploads/1/3/4/3/134318746/fekitagotufuj.pdfIn PDF document text
    • http://auto-fishing-rods1.club/gewetelavalsvqa.pdfIn PDF document text
    • http://rodsfish.club/xolixijeguxeliresomifixonxf4i.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387589/normal_604ca89910e56.pdfIn PDF document text
    • https://cdn.sqhk.co/tejosepu/jzvidhs/pull_him_out_level_80.pdfIn PDF document text
    • https://wimunalowuzew.weebly.com/uploads/1/3/4/3/134360992/4582149.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404976/normal_5fd97b027725c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451028/normal_6056c22c10f11.pdfIn PDF document text
    • https://wilulesutazi.weebly.com/uploads/1/3/3/9/133997377/xevenolap.pdfIn PDF document text
    • https://cdn.sqhk.co/letarezetap/2fjdugc/candomble_religion.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416305/normal_6058189a64119.pdfIn PDF document text
    • https://gozozogedabasiw.weebly.com/uploads/1/3/4/3/134321967/5877811.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373527/normal_5fe754a443bb3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417519/normal_601468f91b7db.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369909/normal_60088e3a4a583.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449183/normal_6009d546ce982.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/dogazisuze/34036099628.pdfIn PDF document text
    • https://s3.amazonaws.com/wixanarer/42299774730.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f8e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E3 5464 bytes
SHA-256: da44c1dec983356855919ac93281beac5840ac9808549807aaae5717012f0336
font_01_sfnt_off00010b63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B63 11076 bytes
SHA-256: 4a4624bed354704e719345a35b567769d266c2c0543eeaf0f52149e843678d81
font_02_sfnt_off000130ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130FF 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176