Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cccf811dae321b2…

MALICIOUS

PDF

71.1 KB Created: 2021-03-14 14:42:44 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 2af978bff1dbbe3bc6f613f1b75580f7 SHA-1: 73873eef58d7ac889b6b5979507563e31b3543af SHA-256: 8cccf811dae321b2a2b5d7319e50e20bb280bc9b9c8d59fd55e3f7277e25edd2
186 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains a large number of external links, many of which point to disposable hosting or redirectors, indicating a link farm or phishing lure. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic strongly suggest an attempt to manipulate search engine results or direct users to malicious sites. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://leonvi.ru/strik?utm_term=coach+quinn+st+rita PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4414360/normal_60166fbd10a13.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413590/normal_6013c198f3938.pdfIn PDF document text
    • http://tuderoba.getenjoyment.net/electrical_engineering_entry_level_jobs_san_diego.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460477/normal_601d799e47643.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e5baaea7-7007-41de-9367-4ebf3ed55875.filesusr.com/ugd/8e1900_b85ae61051ac4066b26548baf9b37859.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/53bc1f87-a429-4fb8-88f0-616fd6a9f0f2/osha_safety_data_sheets_spanish.pdfIn PDF document text
    • https://ca108e69-7b6b-43f0-8f16-d96ebeb8a33d.filesusr.com/ugd/79e0dc_c04c2d40a58045918a844315d341a65e.pdf?index=trueIn PDF document text
    • https://21e323bd-7fdd-46e9-a6c7-4880e76d7610.filesusr.com/ugd/0a51c1_620455fa7f8d4738ba0da5a11656a377.pdf?index=trueIn PDF document text
    • https://1682489e-d94b-4f22-b6a6-c8ecb623ca2e.filesusr.com/ugd/5f226e_ea26c3093e35446180a3c963fe7b77c9.pdf?index=trueIn PDF document text
    • https://77bc4ea4-de20-41c0-a463-a5315db628d9.filesusr.com/ugd/2c69e3_64d899b3a5fc450a8f42c17d3e085458.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea732875-4ff8-4402-8bdd-1cce34f0277b/82913512967.pdfIn PDF document text
    • https://67258aaf-84c5-4a88-bfd2-1aa7ddb6c27a.filesusr.com/ugd/850f07_3e2e1a3d165f4c3385403869330e950f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8c3bbbb6-1614-4e93-aada-92880a8f38d5/13115246772.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15d22d86-047e-41f9-b333-25e6abb07639/gobuwonekufigozu.pdfIn PDF document text
    • http://ziwemasux.myartsonline.com/25528206071.pdfIn PDF document text
    • https://bcd7deca-fd5d-492b-a220-d373ca515bc9.filesusr.com/ugd/12f4eb_ac98d92b082b48568f416659488ac49d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a02e8255-1955-4167-8d4a-a3c2d75e441c/50050449100.pdfIn PDF document text
    • https://72dfff08-f6cb-4f5d-aaac-ebe71175d6a6.filesusr.com/ugd/c268f7_1ec413b33f224200a4d116d220ce4930.pdf?index=trueIn PDF document text
    • https://80d0ab3e-5d82-4547-8f02-ffe19150e389.filesusr.com/ugd/776b9b_447615afc0044e3381b8e6848b1cb0a0.pdf?index=trueIn PDF document text
    • https://d0aee4dd-c5bf-4c29-adcf-3aa844f59ef3.filesusr.com/ugd/193d13_7f6b693014594a59ae142d8787cb69c9.pdf?index=trueIn 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_off0000d904.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD904 4884 bytes
SHA-256: 01ce1bf28f73b99d78618964a1a5724a8f8d6c5dcb23069ab6391cd21ef3b9c8
font_01_sfnt_off0000e998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE998 10644 bytes
SHA-256: f83fa0986cf5fb092a585ef4e4bfc0454b598d32b7f313a44cf1281c1b7626d1