Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4e16041c5ade149…

MALICIOUS

PDF

42.7 KB Created: 2020-10-17 10:51:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 270db769c62d913183c8d5ededc22f3e SHA-1: b88727aff9c3cb7231e7c075aadbccf56027d9dc SHA-256: c4e16041c5ade149ccdc3a3eaf9bf2928e2bb5db79507dc2cd087ddf2a4d340a
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to disposable hosting and are part of a link farm. One URL is identified as a known malicious redirector, indicating an attempt to lead users to harmful content. The ML classifier also strongly flagged this PDF as malicious.

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/strik?keyword=ejercicios+de+formularios+en+excel+2 In PDF document text
    • https://zoxuzuxebexot.weebly.com/uploads/1/3/0/9/130969059/4045700.pdfIn PDF document text
    • https://vezorobabuwej.weebly.com/uploads/1/3/0/9/130969079/1174120.pdfIn PDF document text
    • https://jaserasozupog.weebly.com/uploads/1/3/1/4/131454215/lolazawake.pdfIn PDF document text
    • https://vedabigejiko.weebly.com/uploads/1/3/1/4/131438046/e7bd111eb83ff.pdfIn PDF document text
    • https://pebiname.weebly.com/uploads/1/3/1/4/131453048/454776.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375075/normal_5f89ab9312b0e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366308/normal_5f8a69f8b75b1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371025/normal_5f89ac0075e89.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365552/normal_5f8754b7ea964.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/4975/3493/files/mammals_characteristics_worksheet.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0483/8693/2894/files/46177984853.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/9219/5993/files/vetewitibifabisupa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c6992e47-f0da-49ef-9c55-6c4ab784b2b4/75804639768.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0af93c31-85a6-4692-aa5c-66c120b8cf54/vemexenudikatogugakurat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6377fe9e-a7de-4208-9232-2607bbce8bf2/the_last_president_ingersoll_lockwoo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5979ac8f-c559-49c8-ac0f-c6dfa7fe73ef/rererenesi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/31a2974c-cb57-4715-9874-f62c07978cdd/65520465472.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0853f7a9-789a-483f-9204-5c3f4ad4d347/71622178237.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6e67f858-d3b7-4300-bfd1-9d264105ed14/zixadodusojenabifafiki.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/43add26b-d6bd-4953-b974-785f79c7729d/kuwazikewavasaxawem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a49fabb-2156-4c4d-8248-49ecf33b5745/tonujoponidisoruguw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c171126-9e32-4ba2-8c23-750ccbfea40a/30244885776.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/22fc0d5a-836a-4fa0-8d08-9a929880d28c/xiwonisurubafawakimamosu.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_off00006580.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6580 5400 bytes
SHA-256: 4323de0dd17b7663cf55a1516642c62f19b42098cddf017e5c7c1b542239326a
font_01_sfnt_off000077ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x77CA 10976 bytes
SHA-256: 9bf256c7c062cf255d0d62c8769f445542543f218bdea9b13fbbe428a8c4e25c