Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8786e397f9e0ef6…

MALICIOUS

PDF

85.2 KB Created: 2021-05-24 23:19:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 753ab2bd7ca84c13791cffb9c2652c2e SHA-1: 47c494fab7672e9f7e30ca4448da2a17ccaed025 SHA-256: b8786e397f9e0ef63d20d370c6dd8e0b8fbc65ea106e6920494b02a1e9281a69
126 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spam operation. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure suggest an attempt to redirect users to malicious or spam content, potentially as a spearphishing attachment.

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://bologen.ru/strik?utm_term=diagramme+d%2527accord+guitare+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4418590/normal_5fdbfd6e774fb.pdfIn PDF document text
    • https://fuwamelewupo.weebly.com/uploads/1/3/4/1/134131589/jitegejilotowojuno.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4428331/normal_5ff7840771ff8.pdfIn PDF document text
    • https://sizelelam.weebly.com/uploads/1/3/4/8/134867910/gukojatukesot-gijumivo-pawifudi.pdfIn PDF document text
    • https://rosolovok.weebly.com/uploads/1/3/4/6/134687291/dufunow_malujik.pdfIn PDF document text
    • https://jumufewaxijakuk.weebly.com/uploads/1/3/1/3/131380308/lemosejinotitalun.pdfIn PDF document text
    • https://lesapexif.weebly.com/uploads/1/3/1/6/131637780/bevirosix_zedunibital_xofotaligizolif_tifowamowu.pdfIn PDF document text
    • https://butapakenora.weebly.com/uploads/1/3/1/8/131871909/bikujigapuxiwow_pifixodajobe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485801/normal_6067da3b88cf2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489615/normal_5fd1d2506c4b1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498992/normal_60380e8829dfd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418556/normal_604e693c882cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368768/normal_605528cd1ad1a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421939/normal_5fced9da031d0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406789/normal_600fa3745c1d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446280/normal_6025a60f7cda7.pdfIn PDF document text
    • https://bileravufal.weebly.com/uploads/1/3/4/7/134749654/magopuderimov_xonidavu_kutexurifogur_wujanivid.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393220/normal_6014bc7082809.pdfIn PDF document text
    • https://rabibenexu.weebly.com/uploads/1/3/5/3/135319922/vatosije_renajatug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454803/normal_5fe778a1dfee7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425229/normal_5ff901a2ddfae.pdfIn PDF document text
    • https://lizitizesibegip.weebly.com/uploads/1/3/4/6/134685526/2892329.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/dbb3d17a-af87-4b73-a450-f195ab8f9df8/togigibazibupapojoxet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2273f298-93ac-49bc-bab2-6c1be1cc99e4/poema_corto_en_lengua_indigena_y_su_traduccion.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d3f49840-5a35-4af8-a5b3-55a0b7f157c4/wukegodovu.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_off00010ca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA3 5296 bytes
SHA-256: 1060c3ef5a9b586cdad13d6641be98e8d7eba6dc76036dd2bdddf7fe5ec892cd
font_01_sfnt_off00011ea5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA5 12316 bytes
SHA-256: f24712c4af78514d5381c4c9973ed441bec7aedcb370b605b350e0aeef7c8155