Malicious PDF — malware analysis report

Static analysis result for SHA-256 89420443c57c767b…

MALICIOUS

PDF

72.8 KB Created: 2021-06-13 01:59:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 508038ec55175b78f1601745b5707823 SHA-1: 903a25a76d9360358b93d773ffca5aab66c5b3b6 SHA-256: 89420443c57c767bced0b7bb1d65b431461bd92a42548ddeaffba4d90c980956
194 Risk Score

Malware Insights

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

The PDF document contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm. The heuristic PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM indicate a malicious intent to redirect users. The presence of a 'download button' lure further supports this. ClamAV detection as 'Pdf.Phishing.Trojan' confirms the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nomylo.ru/pbw?utm_term=arihant+all+in+one+chemistry+class+11+pdf+download PDF link annotation
    • https://wagemerefav.weebly.com/uploads/1/3/2/7/132712282/a2539404.pdfIn PDF document text
    • https://fefosixofenovi.weebly.com/uploads/1/3/4/7/134755919/tilog.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450042/normal_5fdfc507548b4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370791/normal_600f46caca519.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4456391/normal_5fed5c94f0560.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404105/normal_603f3ea42712d.pdfIn PDF document text
    • https://wirolubu.weebly.com/uploads/1/3/1/4/131453990/8295996.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495065/normal_606e22f6edbcb.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/0502f5ef-afed-48d6-8ea2-dc490a56d286/28941556940.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8831fef6-cb31-4959-ab04-d0fc4e154f5c/problemas_sistemas_de_ecuaciones_2_eso_resueltos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed410e71-22d9-4cda-8488-dee230f62068/how_much_do_api_570_inspectors_make.pdfIn PDF document text
    • http://kejuziz.pbworks.com/f/94848824955.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d1425a6f-334a-4bed-9bdb-faf8f62d0f37/fifatifaxepafo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/208aae9b-f5ad-445a-8ffe-9313471db7bc/73226372691.pdfIn PDF document text
    • http://wamotarirup.pbworks.com/w/file/fetch/144977130/67806769995.pdfIn PDF document text
    • http://berilizi.pbworks.com/f/pubg_mobile_emulator_detected.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e8fbdfb2-c51f-4100-aff5-baac05f6c9a9/google_maps_api_key_wordpress_free.pdfIn PDF document text
    • http://fevawigo.pbworks.com/w/file/fetch/144901794/office_19_download_iso.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5328fa07-fb47-4064-bc75-29c66e5e7ef8/por_que_hay_que_leer_100_aos_de_soledad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7c524b75-4c7d-4206-8a88-f42b71cc4dc8/features_of_unix_operating_system.pdfIn PDF document text
    • http://xegosigex.pbworks.com/f/38560987415.pdfIn PDF document text
    • http://fujiserefi.pbworks.com/f/murder_mystery_dinner_train_reviews.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_off0000daf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF5 5628 bytes
SHA-256: e68bee77c13367879d755163aefa1ddfeb7bd5df7971f8b1953edda3e7d89a4b
font_01_sfnt_off0000ee0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE0B 11640 bytes
SHA-256: 53f58763e3dc3dd587208650cfc5224deb30fa9c17e98bf34712482618972f67