Malicious PDF — malware analysis report

Static analysis result for SHA-256 23b815d385abd805…

MALICIOUS

PDF

78.2 KB Created: 2021-05-27 04:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 161270ee633cba461c0740771b103b6f SHA-1: ceef72c2411ea74520eab36a2d97a85089c7b0c7 SHA-256: 23b815d385abd805d95fe2fec364213124a8a24b130d13253d26af1814f3c47e
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate maliciousness, specifically identified as Pdf.Phishing.Trojan. The embedded URLs, such as https://bologen.ru/strik?utm_term=how+to+write+the+discussion+section+in+qualitative+research, are likely used to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://bologen.ru/strik?utm_term=how+to+write+the+discussion+section+in+qualitative+research PDF link annotation
    • https://kejedaxuz.weebly.com/uploads/1/3/4/3/134355680/8604946.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454691/normal_5fdc78bf276c2.pdfIn PDF document text
    • https://xezefamije.weebly.com/uploads/1/3/4/3/134352880/3287506.pdfIn PDF document text
    • https://rutukosawokiw.weebly.com/uploads/1/3/4/3/134318214/6c1dfdb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4456667/normal_5fce866a22e59.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495385/normal_602e2a9be7417.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367961/normal_5fdc883a1d04e.pdfIn PDF document text
    • https://jiraxoxaxizare.weebly.com/uploads/1/3/4/0/134012395/1697060.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412774/normal_5ffd8594779dc.pdfIn PDF document text
    • https://wanuwajazil.weebly.com/uploads/1/3/4/8/134899981/2b277af.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/60b35859-99ba-4532-b570-6999c770c568/38552226501.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f0570fb-39ad-4342-8a3e-57db564bfb1d/excel_vba_table_functions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fc0f85e2-3f39-458c-ac27-e8a6a4ac4cc9/22775467593.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8d127c07-2a17-4af4-b883-cd0b19fe4278/rigoligajepujovugonigiwit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4d508ed5-7d7b-4543-916f-3f5eb0be33ce/chuck_palahniuk_net_worth.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8dd57039-8dba-4bb1-946d-0f43d68005af/64068424681.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/09cff0c8-733d-40cf-8ffa-471882938da4/how_to_setup_asus_ac1900.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0e8e4efa-6e83-4d66-acad-b9c5f265a97f/leucocitos_desviacin_a_la_derecha_e_izquierda.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b62c9e72-a87f-40be-9970-634eff47a533/poxidelokin.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_off0000f306.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF306 5268 bytes
SHA-256: e7b0f1ec55fc5f7d7fc454a672742e8e4ec1f4b209e3739732222ac293710eb5
font_01_sfnt_off000104fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FA 10752 bytes
SHA-256: d84a204c8f629fc2b14270e541b0d82266797904ab3e8c45aae42eae8cc90f7e