Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a98dcd670dd2324…

MALICIOUS

PDF

74.4 KB Created: 2021-03-31 03:21:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-28
MD5: b78b6822eb7bf0d83ce88c4e0f201a1e SHA-1: 52afe8bc7c5cf8cae31d57c6de34026a99dccb4b SHA-256: 4a98dcd670dd2324deaee9cc644933db63bb338eac5e33593b81eb8536de3289
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, a technique often used for SEO manipulation or to distribute malicious payloads. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially harmful content, possibly as part of a phishing campaign.

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://vilenefex.ru/wix?keyword=all+the+mathematical+terms+that+mean+opposite+of PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4459929/normal_6053ebced413a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4468563/normal_60056147398dc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447093/normal_60493d4730e84.pdfIn PDF document text
    • https://nikubasixuza.weebly.com/uploads/1/3/0/7/130738960/petepapavafaluku.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453129/normal_5ff896a36d196.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449602/normal_6055ee8fa8910.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413983/normal_5fd7f49ccd937.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4457590/normal_5fcf79c00d107.pdfIn PDF document text
    • https://tuxabonelunod.weebly.com/uploads/1/3/1/3/131379680/fb5358d424d86.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/wuvepilamamuse/frog_dissection_answers.pdfIn PDF document text
    • https://6674166f-eb58-46b1-9d38-a528bc95e02c.filesusr.com/ugd/e38d8e_ef7f3a7bcfa743f2b489ab74ccad1034.pdf?index=trueIn PDF document text
    • https://011f98f8-b45f-4578-a2fd-466b530f7845.filesusr.com/ugd/74e905_4843856932db45fa84287b25f5ea324f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wiremeresegikon/how_to_solve_f_gx.pdfIn PDF document text
    • https://21d44941-995c-48b9-956b-8145330e20d5.filesusr.com/ugd/577b75_2b8504cc5a294556af9f91cb9cc71da8.pdf?index=trueIn PDF document text
    • https://62dace35-232c-43a2-b3e8-6cf19ad57148.filesusr.com/ugd/42ae31_96973b81de5647c2bc0d15b3f544e787.pdf?index=trueIn PDF document text
    • https://f6180879-d31b-499c-8e42-fead7842c491.filesusr.com/ugd/007227_d395823b1928486a99e1f5ce22934872.pdf?index=trueIn PDF document text
    • https://cfae799c-d04a-4395-b2c2-700dffd2ed5c.filesusr.com/ugd/15504a_ab1a32fc509b4cf8aa6ed1a0d0b729cc.pdf?index=trueIn PDF document text
    • https://77ac2d45-d533-4b4b-a85c-01e81860bff9.filesusr.com/ugd/7f1ad7_d440dc8ed0e84489a7cd2905f57876e1.pdf?index=trueIn PDF document text
    • https://95a57b4d-a24c-4412-bd87-88f4f885d252.filesusr.com/ugd/011e4b_9d637e0b4e484c1a8712f005d0fd02db.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tikoweravisixu/veluperurozikupumu.pdfIn PDF document text
    • https://s3.amazonaws.com/jewizopukuni/3833844558.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_off0000e524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE524 5244 bytes
SHA-256: d547f649015b105cbe7cebb3f468faa0d60b452294875763c2bdeff944824017
font_01_sfnt_off0000f6c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C6 10896 bytes
SHA-256: c906db6175fad3cb6dcf9c3f76a836418f0d66bc586a1c29f9705c2f9d60ab80