Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5d2275af792fef6…

MALICIOUS

PDF

70.9 KB Created: 2021-03-23 15:23:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: eb88fe4e0fc5163ed1de0222464147f2 SHA-1: 562d37590e0eb2f168ef2d58f5d20f4d6b8f2f7e SHA-256: b5d2275af792fef61589e9ba3d6372a9bc6cbcb138495eba8927adc585bf66d3
186 Risk Score

Malware Insights

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

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 0.9993

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://dafemum.ru/wix?keyword=8th+grade+social+studies+staar+study+guide+answer+key PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4369514/normal_5ff94ab5c9d6a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459165/normal_601ebd855411a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366350/normal_5fcca1a5bb640.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391954/normal_60134b51c3725.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447253/normal_5fcdc41a20092.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464541/normal_604d29f00a2d3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420030/normal_604d0ac01a13c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413587/normal_604a4308bf8dc.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/vosimalume/juleme.pdfIn PDF document text
    • https://48cc712b-de5e-493e-a198-f8962849e22b.filesusr.com/ugd/d2751c_0b340325065e4e189c043b0175df40aa.pdf?index=trueIn PDF document text
    • https://52431b39-7396-4b0c-bcaf-ab72d449a1bf.filesusr.com/ugd/f8cef3_70f09dcfde9c4be495b16b60fd3a5e0e.pdf?index=trueIn PDF document text
    • https://ac4cd5cf-e861-4b1b-a585-e47049f737a6.filesusr.com/ugd/843280_5e3f3184dbda41e38232ea296e7b689f.pdf?index=trueIn PDF document text
    • https://0e098354-e5d1-4afc-9be7-763a70ae5e44.filesusr.com/ugd/ef253e_f48486123f77477d93845bb4d10d718f.pdf?index=trueIn PDF document text
    • https://0fdd9f25-8366-4660-9463-376fd915ad39.filesusr.com/ugd/c16cf9_53762a3c2a0e492985544c1baec23718.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zedilegol/rebetifiwu.pdfIn PDF document text
    • https://s3.amazonaws.com/bexolamabad/high_school_biology_macromolecules_worksheet.pdfIn PDF document text
    • https://s3.amazonaws.com/bupesejirijejus/crooked_house_movie_parents_guide.pdfIn PDF document text
    • https://4c72699b-aa2e-4dc8-8bd5-1a54e8f938a6.filesusr.com/ugd/f3cb45_369df3f5bc244c4396b45a1c8d5596c5.pdf?index=trueIn PDF document text
    • https://ddd90330-5837-4e0c-b2f6-9383941cd2db.filesusr.com/ugd/568e2c_f3375db2862947b89c2a6cc3f8829f43.pdf?index=trueIn PDF document text
    • https://f4f877d8-29ff-4f35-83ab-971b93db0aba.filesusr.com/ugd/f4de5e_f864e23f66684e2098f7f04c54844ca4.pdf?index=trueIn PDF document text
    • https://c809e8a6-5bdf-489d-8d8c-df4e4638a115.filesusr.com/ugd/45a296_e8c26deb78064217b20058006900157f.pdf?index=trueIn PDF document text
    • https://ad9e3d1f-bb22-46ca-892e-b6aa3325a756.filesusr.com/ugd/837d34_de3cb117cb3a42138a0ea27a2ed12d29.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lixuzo/kasezemuriwoxapozajo.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_off0000d416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD416 5556 bytes
SHA-256: fcff6d69fae4372f7ddf1167e32444fb65ea446c7d7ee55bf1f4ced58da3e40b
font_01_sfnt_off0000e716.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE716 10776 bytes
SHA-256: 09799bc7d270b5b638a7683a0619514cbfd95c2b44f6fa0a5cefdf7826bc9484