Malicious PDF — malware analysis report

Static analysis result for SHA-256 12cbe511eb59ea81…

MALICIOUS

PDF

39.7 KB Created: 2020-10-28 03:37:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 504c8316d616f6cf5d3cad1f3879ddb4 SHA-1: c89965c3ab043e0f82653d4e48d34c4363c6fa91 SHA-256: 12cbe511eb59ea81ae8272b4c68dae72d244714256942adeb745d327092fa745
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded links, many of which point to disposable hosting or redirector infrastructure. The primary malicious URL identified is https://cctraff.ru/wb?keyword=letter%20e%20worksheet%20preschool, which is flagged as a malicious redirector. This suggests the document is part of a link farm designed to lure users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://cctraff.ru/wb?keyword=letter%20e%20worksheet%20preschool In PDF document text
    • https://siregudak.weebly.com/uploads/1/3/0/7/130738759/833092.pdfIn PDF document text
    • https://fotejisatowonu.weebly.com/uploads/1/3/2/3/132302873/750b9e662.pdfIn PDF document text
    • https://fijojonibiw.weebly.com/uploads/1/3/2/6/132681787/rotizizalipi-xulejowo-wegevok-xutijub.pdfIn PDF document text
    • https://tinalolovini.weebly.com/uploads/1/3/4/3/134371967/5573ef.pdfIn PDF document text
    • https://wilunozuwi.weebly.com/uploads/1/3/4/4/134432110/vepuwenoxi.pdfIn PDF document text
    • https://jemiwuwavaza.weebly.com/uploads/1/3/0/8/130814288/rijelo.pdfIn PDF document text
    • https://zavisedifigi.weebly.com/uploads/1/3/4/3/134316550/rebevuratijula-kikozejidejuza-sufilobujem.pdfIn PDF document text
    • https://rofexigu.weebly.com/uploads/1/3/0/7/130738805/e0e40.pdfIn PDF document text
    • https://fulodovujigiw.weebly.com/uploads/1/3/4/0/134016909/f1c63e59bcf16.pdfIn PDF document text
    • https://letateworu.weebly.com/uploads/1/3/4/3/134365764/puxipovib-finurizoki-fufipu-gigeretomo.pdfIn PDF document text
    • https://keniwuki.weebly.com/uploads/1/3/1/4/131483234/bf4458.pdfIn PDF document text
    • https://goduvozimaku.weebly.com/uploads/1/3/1/3/131380582/puzezowapijewaduk.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/3589ef15-06bb-4976-9d6a-3f8dfd3013a4/25111293835.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a98188b3-65a5-489c-91f6-07b9a47348f1/vokajik.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4bfb1cc-8376-4cd7-9ade-55795178e52e/rafeposibezexo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd35adf8-0918-4a55-ada8-a1bdee6c939c/30755347854.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ced9c5e-24f1-44bf-900a-18220fe74012/cphq_exam_secrets_study_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/zalomi/online_editor_to_ms_word.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0de050e-c693-40b0-a474-bb2b3ef0a119/3937698660.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/59714fa5-51c2-4974-a746-1d8a60dd2da7/ximuzuwurofonaziwo.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_off00005b00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5B00 4908 bytes
SHA-256: f8aacf8dc86f541caf97de7b9492ecfb4758920a33488a7a8dd470f7c2eb83b9
font_01_sfnt_off00006bc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6BC9 11080 bytes
SHA-256: 9206ac05568bf93d8360056003ecb9dfb98d3bb9b10cbc162d3d844fd9505bee