Malicious PDF — malware analysis report

Static analysis result for SHA-256 c475f8b7bc621d3a…

MALICIOUS

PDF

87.3 KB Created: 2021-05-26 19:44:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 738108c4b92d5b87bd260054615e5a6d SHA-1: ef96da92e941a18a40684dcfb2d138e3a87cff26 SHA-256: c475f8b7bc621d3a8757f719df7a35a733be8e0a9588a6ad77ce3577bc5dcbe0
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs and is flagged by heuristics as a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains references to 'arithmetic reasoning practice test pdf' and 'wkhtmltopdf', suggesting a lure to disguise the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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 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://resalured.ru/strik?utm_term=arithmetic+reasoning+practice+test+pdf PDF link annotation
    • https://wasexakenisopi.weebly.com/uploads/1/3/5/9/135982815/8711551.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484370/normal_5fe083fc8e18d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490366/normal_606976465028d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477873/normal_604a6a3241e73.pdfIn PDF document text
    • https://jibeguviju.weebly.com/uploads/1/3/4/7/134723477/runudobef.pdfIn PDF document text
    • https://ninisezidopif.weebly.com/uploads/1/3/5/3/135391617/9929248.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425227/normal_606b22576c2af.pdfIn PDF document text
    • https://nexezosig.weebly.com/uploads/1/3/4/4/134460983/kawaxikomofeza.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4497348/normal_5fffc06708ea5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393186/normal_601a730db40b7.pdfIn PDF document text
    • https://suxokigivulumu.weebly.com/uploads/1/3/4/4/134479742/c55ca38592281fc.pdfIn PDF document text
    • https://vafukited.weebly.com/uploads/1/3/4/0/134017527/9e742e83b7ec12.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409606/normal_5fcc2eb484880.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481275/normal_5fedbd759786e.pdfIn PDF document text
    • https://figiroxofidun.weebly.com/uploads/1/3/0/7/130740151/lobufukat.pdfIn PDF document text
    • https://jedifubebevaze.weebly.com/uploads/1/3/4/8/134873515/1361609.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458837/normal_5ff6828c28be4.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/8b52756e-8c11-43b5-b65e-8c380d401397/99708543353.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8a2ed5ef-026d-4208-a07b-fb4fda6b2202/nonugezozapirexawuvunigu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/166b1795-bef0-44b3-8b78-b200437315c4/62286656499.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c4a0fa9e-afdc-4d5b-a94e-3e0f352a9d8b/wimalut.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a1393f2b-a106-4f6c-95c5-030d3cc8eb97/zefuvo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/555cdc84-56f5-47c3-819d-0630ecbfa4ce/mary_rowlandson_a_narrative_of_the_captivity_and_restoration_of_mrs._mary_rowlandson.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9b24008-d4b1-4f80-a32e-6001184eb531/31310786354.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_off000113d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113D5 5528 bytes
SHA-256: 4f40c425516240c426e5ebcf0c9bb2c5e2da5cfc190ce75fb49c14c2b2e6eb9a
font_01_sfnt_off00012672.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12672 12100 bytes
SHA-256: d9b2932f68ce8cd7f6cb6562b7a31c81101b1c4dd7223ba0f7cdd8ae009858bf