Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca37fb8364a08bc3…

MALICIOUS

PDF

70.7 KB Created: 2021-03-16 06:59:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 4f05be91d99f8ec167c4a929792d75fa SHA-1: d4204af642841ec11a188329f225df51ab6de053 SHA-256: ca37fb8364a08bc3494556a9b5e0d17f538151254f7f2c559f75a27aff013e12
186 Risk Score

Malware Insights

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

This PDF file contains numerous external links, a common tactic for SEO spam and phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to 'little grass valley reservoir fish species', directing users to a URL that likely hosts malicious content or further phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://bologen.ru/wix?keyword=little+grass+valley+reservoir+fish+species PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4453117/normal_6022739518b9b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498986/normal_5fe67808ee5de.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421039/normal_6048196056d4b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459318/normal_602554d9b70b7.pdfIn PDF document text
    • https://tujozidu.weebly.com/uploads/1/3/4/6/134694944/b8c83.pdfIn PDF document text
    • https://mavosawiki.weebly.com/uploads/1/3/1/1/131163846/rowulofixinipol_vonikisesa.pdfIn PDF document text
    • https://donabetolemi.weebly.com/uploads/1/3/1/6/131637402/buwavelewo.pdfIn PDF document text
    • http://mimasajikataza.iblogger.org/synthetic_polynomial_division_worksheet_2_answers.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474448/normal_603434934ca8e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465539/normal_5fdecc858cb4b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413846/normal_5ff2fa80ab576.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412593/normal_5ffffa58b968a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414849/normal_5fea2caf7575f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wivunonovef/61690880999.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a0b5531-42d9-42f2-818f-dc8cb6afa0c7/amplificador_de_audio_para_casa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4cd50589-ea27-4bca-8557-e2738f982482/sonose.pdfIn PDF document text
    • http://jomewuborova.rf.gd/51324475791.pdfIn PDF document text
    • https://s3.amazonaws.com/muvemasoxaji/27188604270.pdfIn PDF document text
    • https://s3.amazonaws.com/vawoginele/how_to_read_transunion_credit_report_canada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db6ff2bb-296e-4693-bece-cd0dd40b7a3d/trigonometric_functions_geometry_definition.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ac5825a-18d6-4d57-a119-c4a3b4e92331/10984903990.pdfIn PDF document text
    • http://sojidalome.rf.gd/solefa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca11f630-2495-49c7-8171-ad1513db2fcb/sexixedaki.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_off0000d5d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D7 5380 bytes
SHA-256: 73bb92b13d0c6acd066ad1f3aa3f89d21de09f5d110e22b44dae8bbf569de8b7
font_01_sfnt_off0000e838.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE838 10440 bytes
SHA-256: ac022c079e1c6e65700dab8cb8d6e720a5b8a5fe99d61e0d32c738e65e58d15d