Malicious PDF — malware analysis report

Static analysis result for SHA-256 4825936856523c0d…

MALICIOUS

PDF

77.4 KB Created: 2021-05-24 00:49:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 423f84ef59fb6662e9af086974bc6af4 SHA-1: 04a0fa998f106d06ebc8271b0bf50a5caf653ebb SHA-256: 4825936856523c0d1b99aac6271c6ce712029fe2cade4b171e9cfeb022e4f6ec
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing lure. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users. The heuristic 'SE_BROWSER_INSTALL_LURE' indicates the document likely prompts the user to install a browser extension or update, a common tactic for credential harvesting or malware delivery. No scripts were extracted, but the presence of numerous external URLs and the social engineering lure point towards an attempt to exploit user trust for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • 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 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.
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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+is+chat+message+tracker PDF link annotation
    • https://vavaxurose.weebly.com/uploads/1/3/0/7/130775274/1524838.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4384152/normal_5fcd82afe1d8f.pdfIn PDF document text
    • https://wamogipoko.weebly.com/uploads/1/3/0/7/130739383/2366143.pdfIn PDF document text
    • https://latitatuforuza.weebly.com/uploads/1/3/1/3/131398212/woripaxegone.pdfIn PDF document text
    • https://vorexumezekadan.weebly.com/uploads/1/3/0/9/130969740/kukidokorebo.pdfIn PDF document text
    • https://dijanofubor.weebly.com/uploads/1/3/4/6/134605157/nerapuvewegamuvokud.pdfIn PDF document text
    • https://simidolipuxemit.weebly.com/uploads/1/3/4/4/134486986/665f70f777ab49.pdfIn PDF document text
    • https://vulalubog.weebly.com/uploads/1/3/4/8/134862436/busodaba.pdfIn PDF document text
    • https://pilidikuvitas.weebly.com/uploads/1/3/4/7/134766888/pofejiferanirobux.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4444655/normal_5fcef564d908d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500183/normal_5fd2f20370d0a.pdfIn PDF document text
    • https://sijetuso.weebly.com/uploads/1/3/4/4/134499475/25162c945f3d1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390055/normal_6036bbe33455d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414701/normal_5fd70bd4ee3cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381988/normal_606e89a54531b.pdfIn PDF document text
    • https://mebavobof.weebly.com/uploads/1/3/4/5/134592521/xinipupug_bifuke_dopasi_nupipiz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448735/normal_60280f9285674.pdfIn PDF document text
    • https://gobajirosalafos.weebly.com/uploads/1/3/5/3/135392744/30e0a1c.pdfIn PDF document text
    • https://kutikeso.weebly.com/uploads/1/3/4/4/134490414/6574188.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475563/normal_60340045d1ebb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426421/normal_5fd065edeafc1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000f006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF006 5260 bytes
SHA-256: 812ba056e22bbbf811ae9b388a58362571b3dae1a5bade09e1d50f19522cedbd
font_01_sfnt_off000101c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101C6 11088 bytes
SHA-256: 3976721636dbf27ef5a102028dd9f9391d6215fd81cfdec1706e1d1027c9b49d