Malicious PDF — malware analysis report

Static analysis result for SHA-256 691d19ced8048387…

MALICIOUS

PDF

71.6 KB Created: 2021-04-04 21:12:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: a49b45372b2e0b0f4863f20060aa3321 SHA-1: 98afc0cbcbe030cfda469344e54764f2ffd9d46e SHA-256: 691d19ced8048387ef1c02f5c4d52698e3faf367501ba3c6a9d0f6be1ea13bfc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, identified as a link farm. The ML classifier strongly indicated maliciousness. The primary purpose appears to be directing users to a multitude of other PDF documents hosted across various domains, potentially for SEO manipulation or to serve as a distribution vector for further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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://soxebez.ru/123?utm_term=comreg+quarterly+report+2018 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4489716/normal_5fef10ac36ea4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501501/normal_6015e49075f0a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402519/normal_60686bc7908b1.pdfIn PDF document text
    • https://xizuzumuk.weebly.com/uploads/1/3/2/6/132682261/wajopuv_gewuvipemax_wefibo_finodizi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413865/normal_604a74745bc90.pdfIn PDF document text
    • https://pibezenasa.weebly.com/uploads/1/3/1/4/131454503/c8654197525e.pdfIn PDF document text
    • https://bevabuje.weebly.com/uploads/1/3/4/8/134897483/6263137.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374979/normal_5fce4fbe9c146.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490930/normal_60205238ce3ce.pdfIn PDF document text
    • http://jetulugu.iblogger.org/is_operations_research_difficult.pdfIn PDF document text
    • https://gukevejulolun.weebly.com/uploads/1/3/2/3/132302942/65cc0e999ae01.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417406/normal_604eb9b3b32de.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/30928236-2ec8-4cd5-867b-ed272c76e484/shepherd_me_o_god_youtube.pdfIn PDF document text
    • https://5a6df620-610b-4d6f-8f1b-71e936bb70bc.filesusr.com/ugd/1f5cef_67e0dde9096c46bb9194dc05742f615e.pdf?index=trueIn PDF document text
    • https://728bf1be-24e3-4891-ba98-fedceca1a503.filesusr.com/ugd/3268c8_36599730cfd348259c00746aee4c7b96.pdf?index=trueIn PDF document text
    • http://vukelas.rf.gd/why_has_my_dyson_fan_stopped_working.pdfIn PDF document text
    • https://cf176ec6-4820-456b-adf9-61e5f06c968f.filesusr.com/ugd/43d598_d72ef1192778468689224ae1c04b0dc3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d82ff65d-8070-41fb-bb06-ec9bd5945aac/aula_internacional_1_audio_free_download.pdfIn PDF document text
    • http://javasuk.epizy.com/picsart_latest_version_cracked_apk.pdfIn PDF document text
    • https://144ece88-722e-4d59-a9d1-ae16887514c2.filesusr.com/ugd/48b17f_45b6318e3f33440fbc76eb81dba52f5f.pdf?index=trueIn PDF document text
    • http://katufimeg.rf.gd/pukavaxugipijobipitokof.pdfIn PDF document text
    • https://c140f178-ee45-427e-91fe-a3c5f821f67e.filesusr.com/ugd/ebc5f9_0476605f7f8749ea92bed815c10f7926.pdf?index=trueIn PDF document text
    • http://pefegazafil.epizy.com/51971966075.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_off0000d8de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DE 5612 bytes
SHA-256: df73f91755c4a180bea8561683f98530d7dfa82063f615943159b10399d5e913
font_01_sfnt_off0000ebea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEA 10584 bytes
SHA-256: 944621535788e4c6f8d1d2b9a4d64948de97a471308b5a7ce3885e5ca36e93f3