Malicious PDF — malware analysis report

Static analysis result for SHA-256 bac81faf334de900…

MALICIOUS

PDF

81.8 KB Created: 2021-03-20 13:18:14 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: d78fb44080251ec6fe6e94ddbfa18f35 SHA-1: ab4c3fae10b6e393b484489dfe9fa0ba16097ee7 SHA-256: bac81faf334de900d57b11a179716a8db8c355969a9245cbaebd0373b8e6f042
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and numerous URLs point towards a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 6

  • 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.
  • 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://kuzutuzo.ru/award?keyword=cds+2+syllabus+2020+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4465702/normal_60072fa4c76bd.pdfIn PDF document text
    • http://lojapidabud.mypressonline.com/paxevug.pdfIn PDF document text
    • https://suzexefovewav.weebly.com/uploads/1/3/4/6/134640410/gunevopezoxufug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376852/normal_6018f775d1178.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498978/normal_601e151869053.pdfIn PDF document text
    • http://pasiworuwiwoz.getenjoyment.net/spring_framework_tutorial_point_free_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390381/normal_6040dbc2526a1.pdfIn PDF document text
    • http://medebupima.sportsontheweb.net/is_a_hub_layer_1_or_2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413118/normal_601743d2d1d4f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376374/normal_60121667abdbe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392191/normal_5fd6446f2edf3.pdfIn PDF document text
    • https://milonotupilo.weebly.com/uploads/1/3/5/3/135347339/447ff86ff0cec0.pdfIn PDF document text
    • https://wozijosetat.weebly.com/uploads/1/3/1/4/131407158/rozeregulotaradive.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366317/normal_603afa14e5d25.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388819/normal_601731f451766.pdfIn PDF document text
    • http://forisawidokomor.sportsontheweb.net/zidunakidekutoligiwek.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416319/normal_60343a0052d36.pdfIn PDF document text
    • https://vunidiripoga.weebly.com/uploads/1/3/1/4/131453449/2998992.pdfIn PDF document text
    • https://fotijaxak.weebly.com/uploads/1/3/4/1/134108731/wekavilatuzugowixu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389823/normal_602056c6b7c22.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d64d5b41-a66a-4b78-b87f-0feaf8e9cf76.filesusr.com/ugd/cf1aed_e343af68d3884c5f8bb9128aad58c18d.pdf?index=trueIn PDF document text
    • https://3485775d-af35-4505-8fb4-f6750f575e04.filesusr.com/ugd/42f18e_8a4b67bf649e49719864d96b39efb363.pdf?index=trueIn PDF document text
    • https://8d59741e-369e-44be-b01e-8fbcb09d2d01.filesusr.com/ugd/7cefa9_7d02897e07c849599c2e192175307792.pdf?index=trueIn 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_off0001022e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1022E 5360 bytes
SHA-256: 57c45040a2fd2c63c70d3e5dc906dc49cefa4271ea95029f0616788d56766989
font_01_sfnt_off0001147b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1147B 11036 bytes
SHA-256: 567ff3f0e8a83cb8942dc79d8f5f0a1bc5138ea2eebc5e52c55b124e7dfd8382