Malicious PDF — malware analysis report

Static analysis result for SHA-256 aad07af196a0e5e4…

MALICIOUS

PDF

93.0 KB Created: 2021-05-09 19:18:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: f41022e837b1abc9bd796827705e40e3 SHA-1: 50afe0d70938d95f16a4cc488ba1864a5625938e SHA-256: aad07af196a0e5e466942ed22c3d1c109ec4001074f1a4d84981902354a4e7f5
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a large number of external links, with one prominent URL leading to a suspicious domain, likely for phishing or malware distribution. The document body, though heavily obfuscated, suggests a lure related to a 'Psych 101 final exam'. The presence of PDF_SEO_LINK_FARM heuristic indicates a link farm, a common tactic in phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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.
  • 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://resalured.ru/strik?utm_term=psych+101+final+exam PDF link annotation
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6739ca04-605d-4ff4-b4c9-4e5bd75a7819.filesusr.com/ugd/031dda_f8b7abd842ba469aa3d036b868030415.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vuzotisenixava/wenis.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/36638e19-9c41-4b81-a956-459c989fb928/mazezadasaw.pdfIn PDF document text
    • https://s3.amazonaws.com/vifusupegiza/delaw.pdfIn PDF document text
    • https://e082cb0d-9c22-4a21-acb7-e2c6127a51d3.filesusr.com/ugd/ff0c06_4161e72a96ee46c1ac49577b5a67f427.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/toniseligiwuzux/sutesixufite.pdfIn PDF document text
    • https://s3.amazonaws.com/mejifavo/mrs._bastianich_manuali.pdfIn PDF document text
    • https://s3.amazonaws.com/forupokisip/nordic_track_ski_machine_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/67406a67-a6af-4136-b742-0f82b5d9c5e8/57634081671.pdfIn PDF document text
    • https://s3.amazonaws.com/kulinisokakewi/21613506353.pdfIn PDF document text
    • https://s3.amazonaws.com/wamatasamegu/how_to_use_app_bundle_in_android.pdfIn PDF document text
    • https://s3.amazonaws.com/nufidibodudulad/contrato_de_arrendamiento_casa_habitacin_baja_california_para_imprimir.pdfIn PDF document text
    • https://s3.amazonaws.com/zulezov/61420339867.pdfIn PDF document text
    • https://0ddd2631-58c7-464c-86d0-a5d1d8121c04.filesusr.com/ugd/301b85_5bd8d393ba894242b775529d827750d7.pdf?index=trueIn PDF document text
    • https://d71fc03c-aea6-48f7-a990-8afffb22108d.filesusr.com/ugd/3de8a6_8202064da915440d80d4d99c0662533a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/setigafat/wododup.pdfIn PDF document text
    • https://s3.amazonaws.com/genedonapubefe/grade_5_math_worksheets_free.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_off00012cd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CD3 5388 bytes
SHA-256: f86328c637c1eadc92598fc919236729edf30d36a3c684a5eed20bb3403a32ff
font_01_sfnt_off00013f23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F23 11400 bytes
SHA-256: c7efddf0c2c838c7bc461d76316cef3b727fdec4fc6ed75aac6f21ffa5ac436d