Malicious PDF — malware analysis report

Static analysis result for SHA-256 11daff0a053e798c…

MALICIOUS

PDF

80.3 KB Created: 2021-03-15 10:40:09 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: a1de5a828f3aa2c17420833a1107b4ba SHA-1: d8b563249e50b3aa14ae1cee5b67edf89fd1e90b SHA-256: 11daff0a053e798c0d26beb781b769daeed000b2c7c8a2a1a7148acbf67cb1ad
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, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the use of embedded JavaScript for redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://nipisod.ru/award?keyword=categorie+catastali+2020+pdf PDF link annotation
    • https://cdn.sqhk.co/mowukirew/ghfjaIX/leave_of_absence_letter_template_primary_school.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408187/normal_6025477f7d94b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4479237/normal_5ffe924f8ad48.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420431/normal_603ed5951c174.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468553/normal_602f467b89cd2.pdfIn PDF document text
    • https://cdn.sqhk.co/lazuxorus/suhgchM/kawasaki_pneumatic_tools.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410985/normal_600ba51e55d5c.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/7708e431-493a-41aa-a13e-d1638fea796f/febixedu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e28c50c-0baa-43e1-a5cd-e41361568afc/9012154011.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/479aa163-8304-4ad4-b411-cbfb7083c001/lenovo_y500_nvidia_drivers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95130142-b271-41e3-844e-11ad2ffe987e/sagavemuxibabigelo.pdfIn PDF document text
    • https://00407fa8-a9ef-4b78-9bbe-46147fc8acf6.filesusr.com/ugd/5ecadc_2992e36426ed46dc84d190b869083387.pdf?index=trueIn PDF document text
    • https://153f2bed-3501-4ec5-9468-ed1987511f6d.filesusr.com/ugd/f67134_3a6c722ccb374d91b5fbb159f1cf1dd3.pdf?index=trueIn PDF document text
    • https://8fc1c2d6-49ba-4d63-8b95-0327ef2b1627.filesusr.com/ugd/1849a1_aeec9fc5ce3b492ea7d34f099c09e7c0.pdf?index=trueIn PDF document text
    • https://0e67983c-e844-40c9-b604-97311ec94efe.filesusr.com/ugd/6e13d9_77583bfb7077445fa611f52fa69efa91.pdf?index=trueIn PDF document text
    • https://f815f12b-539f-4060-8ed9-abd2caada31b.filesusr.com/ugd/ceb2e8_5cd1412f4369496f8fffd82d416c88a2.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pivetuzadujo/kleenex_tissue_box_template.pdfIn PDF document text
    • https://91ca87c2-c493-4616-adaa-fbcec45394e1.filesusr.com/ugd/6116da_b917e0b0918a463ebc21441899c4a307.pdf?index=trueIn PDF document text
    • https://c01188fd-d8af-4b86-846b-090f7ecd58d8.filesusr.com/ugd/9058e5_78a45d7a137345aba7b1fb0439150dfe.pdf?index=trueIn PDF document text
    • https://fd7a53fe-11c1-4e60-83ad-ac1bb997268f.filesusr.com/ugd/5cf23b_7bffaabb24194ca6a486dbdbf5cfa11e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c5acb14-07ff-4fb7-9a13-d4c4b6857933/murugakisuror.pdfIn PDF document text
    • https://s3.amazonaws.com/rodakarugupoko/91150999039.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_off0000fb98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB98 5504 bytes
SHA-256: 0e67fbe1f575c8af6a94d591fa33f38ea4ca6d479d1a50aced0ec8bd21ec1529
font_01_sfnt_off00010e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5D 11420 bytes
SHA-256: 1cf0ccdef67a8941ad34bb999918149287c73d6396107af41d91bcc92db8eb9d