Malicious PDF — malware analysis report

Static analysis result for SHA-256 990623d7fb99be0f…

MALICIOUS

PDF

76.3 KB Created: 2021-06-08 14:44:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 4020da1bba495c4608e68bae8e078c21 SHA-1: 022e312d7b0005fb4af5c4d6a8c74d3ff1d072ea SHA-256: 990623d7fb99be0fda85cd40125fee246609f21132cbcf37bf0e2d00af129343
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting, suggesting it functions as a link farm. One of the extracted URLs, 'https://jottigo.ru/123?utm_term=laptop+brightness+control+software', is suspicious and likely part of the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • 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.
  • 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://jottigo.ru/123?utm_term=laptop+brightness+control+software PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4368746/normal_5fcbf28380c14.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470961/normal_6068be37e6f3d.pdfIn PDF document text
    • https://xuxijewurinawux.weebly.com/uploads/1/3/4/6/134699439/3764257.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472182/normal_5fd17922139b8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427506/normal_606c301ac9676.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449177/normal_6058bebe4f3bf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376086/normal_601e8c3dac878.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416664/normal_6059829154ab0.pdfIn PDF document text
    • https://bowemubunewoseg.weebly.com/uploads/1/3/0/7/130739536/5642959.pdfIn PDF document text
    • https://tewizoduwab.weebly.com/uploads/1/3/5/3/135341898/pulabalunipuxa.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/98842b26-8101-494e-b8cc-c8e32f54ff47/the_firm_john_grisham_audiobook_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7c981e24-2fb9-4af2-8d0c-1a04495d725e/ielts_writing_task_2_band_7.5_sample.pdfIn PDF document text
    • http://gesugot.pbworks.com/w/file/fetch/144859659/laundromat_business_plan_sample.pdfIn PDF document text
    • http://ruwomodanom.pbworks.com/f/itms-services_actiondownload-manifesturlhttps_www.cokernutx.com_cokernutx.plist.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/36d6ce66-4823-4890-8d95-735affd8a5f7/stampys_lovely_world_episode_12.pdfIn PDF document text
    • http://dadilotofexi.pbworks.com/f/did_you_hear_about..._math_worksheet_answers_b-37.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d4de7c2e-1a9b-4b7d-8ae9-7a4a99f97cb8/how_to_make_car_decals_with_permanent_vinyl.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af123b6b-a421-444c-a7b9-cddcaa57d250/simbolos_de_diagramas_de_flujo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/90531fee-f77e-4f40-bdaa-7873f365bf1d/76268155253.pdfIn PDF document text
    • http://bizogug.pbworks.com/f/zojipilokesip.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4bdaa9a2-37e6-41c2-8905-d72add43ac1c/vofinesewexojiniziwo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01e96702-83a1-49db-b199-7196d7503a95/how_to_use_android_auto_in_malaysia.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_off0000ecbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECBC 5448 bytes
SHA-256: 161178b9d7d4b8de2a5898829a4a8c5619cd2d0075fd86108950c936db360c05
font_01_sfnt_off0000ff56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF56 10544 bytes
SHA-256: 3652d1e9a0d61f0d081a4019fa04d68b05a1c87b39c3525f6742b096df79b88b