Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4253172b6e16e8c…

MALICIOUS

PDF

76.7 KB Created: 2021-06-01 16:47:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 841ceb5d96e2d12bc9e8c1d83d35801e SHA-1: 7128788317932d5c10b139bae909af1248bf8ddf SHA-256: b4253172b6e16e8cf07696956009b084db713fc5dd22581dba4b32e6c32fa368
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://krisoc.ru/pbw?utm_term=what+is+the+best+food+for+dogs+with+ibd PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4365656/normal_600321a5428ce.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393035/normal_5ffdb98888947.pdfIn PDF document text
    • https://jubipolofolexi.weebly.com/uploads/1/3/2/3/132302872/zikejozisivu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456671/normal_604729cf3e0d1.pdfIn PDF document text
    • https://kutujenedida.weebly.com/uploads/1/3/4/7/134759749/dugosura.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4466161/normal_5fee7ac8d7e0d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455672/normal_604dab831d5eb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499282/normal_6048a6f7cf371.pdfIn PDF document text
    • https://kamedewogivazu.weebly.com/uploads/1/3/4/0/134096977/f2a0bd768a54.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470696/normal_5fdb94d1a5a81.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366958/normal_60161e6a3f5dc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414680/normal_6057b0e07e619.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://munonoraze.pbworks.com/f/goal_setting_worksheet_for_college_students.pdfIn PDF document text
    • http://xedidovetaw.pbworks.com/f/32929135974.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5508b72d-c0a3-46f4-b7dd-1e9782543e47/academic_text_structure_meaning.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6e74cf7a-5375-4d92-a1b4-aef9a02b0300/vakerobegoboximekuzok.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8afbbdd-0238-4b07-b6c9-2216a7414899/6794957002.pdfIn PDF document text
    • http://funinupun.pbworks.com/w/file/fetch/144426966/how_to_get_into_epic.pdfIn PDF document text
    • http://kibumezi.pbworks.com/f/what_is_modern_architecture.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/820464e5-f8e5-4be9-846f-4f168838ece2/zukazatokegenuwujemal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7bdc0eb6-74d1-4cd7-865a-335a6474e13c/zejusitewisavun.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d8d8791f-b32d-45ae-8007-79e21e983e69/dotabavogexakulimugepimud.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_off0000ec66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC66 5380 bytes
SHA-256: c2973922736a5db696b9f63ab23af1ebc364b17f12ac2b34df227ed5a3496ab5
font_01_sfnt_off0000febd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBD 10804 bytes
SHA-256: e7cf0578afc658aa9e68b90daa7727bc44bea7c1cd0b30281defa34da9cc660b