Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fc8723fbdcea332…

MALICIOUS

PDF

79.6 KB Created: 2021-05-20 07:10:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: d9702c64927f02bebf1df375b01166b2 SHA-1: 036165f4426aadf934c995d4194b65f365cfd8b2 SHA-256: 4fc8723fbdcea3323a074fd70a76fe8e1603b76c20c882e50f820773ce323af3
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV. It contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or SEO manipulation scheme. One of the embedded URLs, https://kuzutuzo.ru/strik?utm_term=annual+leave+request+letter+template, is likely part of the lure. The PDF structure and embedded content indicate it's designed to redirect users to these external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://kuzutuzo.ru/strik?utm_term=annual+leave+request+letter+template PDF link annotation
    • https://fanesorugetefex.weebly.com/uploads/1/3/1/3/131383934/649511.pdfIn PDF document text
    • https://pavadugubuwab.weebly.com/uploads/1/3/4/3/134309483/rasufosus.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454562/normal_605ef6bac89fb.pdfIn PDF document text
    • https://xoxomedeze.weebly.com/uploads/1/3/5/3/135308121/bokemis.pdfIn PDF document text
    • https://vibofizetukoz.weebly.com/uploads/1/3/0/9/130969748/5b88dc0c5915.pdfIn PDF document text
    • https://xuwobonamufaguw.weebly.com/uploads/1/3/5/3/135315698/turukanus-lezekonuzaro-rupaxupanusi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409095/normal_5fdff1b91d4ed.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461249/normal_5ffe468929b48.pdfIn PDF document text
    • https://sojabejob.weebly.com/uploads/1/3/4/8/134890412/varozuvogajor-gagemuna-jepidagakejereb-tinipanaju.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426269/normal_5fd889a516e40.pdfIn PDF document text
    • https://govobozof.weebly.com/uploads/1/3/5/3/135315692/602a08d539419.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385424/normal_5fec237af066c.pdfIn PDF document text
    • https://viwoxewadekam.weebly.com/uploads/1/3/4/0/134016770/suvelafakuzazagufi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451229/normal_5ff8af2d5c976.pdfIn PDF document text
    • https://nutikatike.weebly.com/uploads/1/3/4/6/134601603/58591c9.pdfIn PDF document text
    • https://bododomeliba.weebly.com/uploads/1/3/1/4/131408614/jadikekukigun.pdfIn PDF document text
    • https://kejuzeke.weebly.com/uploads/1/3/4/4/134456394/jajaxavu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468812/normal_5fd966c56fdf3.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bejikefowu/tivuj.pdfIn PDF document text
    • https://s3.amazonaws.com/godoremitiwuja/85553580239.pdfIn PDF document text
    • https://s3.amazonaws.com/kafises/addition_worksheets_printable.pdfIn PDF document text
    • https://s3.amazonaws.com/xokebore/vixiwuzelimiguvolu.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000faa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAA8 5140 bytes
SHA-256: 0bbc96bb69d990316ec93c8d53f563fef7e1d9b049da742711e4914b793817c7
font_01_sfnt_off00010c19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C19 10836 bytes
SHA-256: 97079036c7695f64975f89573ecad567b3abebbeccf283245a657c5fad30a929