Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b11ce7cc2f1fc87…

MALICIOUS

PDF

77.1 KB Created: 2021-06-08 12:01:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 3eb5e6b0f72fd4db8ceb8b5f1f828de2 SHA-1: e500014008503fe3bf2380a539d467bbb16da9fb SHA-256: 4b11ce7cc2f1fc87669e872795407044c3095e42fe97b3ba0a15eea86e1b3b84
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable domains, which is characteristic of SEO manipulation or phishing campaigns. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to potentially harmful content, likely for credential harvesting or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nomylo.ru/pbw?utm_term=how+to+get+medium+of+instruction+certificate PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4409814/normal_603c5f8b4fa59.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374859/normal_604b3138426ec.pdfIn PDF document text
    • https://nitowapesapu.weebly.com/uploads/1/3/4/4/134442046/kodudawupakuku.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503874/normal_605d6cc710291.pdfIn PDF document text
    • https://kibalenujodoziz.weebly.com/uploads/1/3/0/7/130776895/jarol.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495059/normal_60360d0adeb92.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425010/normal_60663b82306ec.pdfIn PDF document text
    • https://wunaramalus.weebly.com/uploads/1/3/4/5/134576193/wumowugiraluter-gomumisijabev-zunetezabadewaf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404515/normal_60144b9314d36.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417139/normal_5feaf7ff8f7ee.pdfIn PDF document text
    • https://kesafukiwunutab.weebly.com/uploads/1/3/4/9/134900694/9fafb001.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://mivegaz.pbworks.com/w/file/fetch/144723384/open_closed_and_isolated_system_in_thermodynamics.pdfIn PDF document text
    • http://zufogopojut.pbworks.com/w/file/fetch/144492363/how_is_benvolio_important_in_romeo_and_juliet.pdfIn PDF document text
    • http://buvavipoluvu.pbworks.com/f/2.pdfIn PDF document text
    • http://zewalar.pbworks.com/w/file/fetch/144454257/kojujusi.pdfIn PDF document text
    • http://buvavipoluvu.pbworks.com/w/file/fetch/144775389/23053905221.pdfIn PDF document text
    • http://fevawigo.pbworks.com/f/admiral_dryer_aed4675yq1_manual.pdfIn PDF document text
    • http://niluputevi.pbworks.com/w/file/fetch/144452202/46652738516.pdfIn PDF document text
    • http://fodorafirig.pbworks.com/f/nefaxinotero.pdfIn PDF document text
    • http://natofuke.pbworks.com/f/kark_karadeniz_arklar_mp3_indir.pdfIn PDF document text
    • http://depowota.pbworks.com/f/4598082659.pdfIn PDF document text
    • http://gufabewa.pbworks.com/w/file/fetch/144479304/76017277963.pdfIn PDF document text
    • http://jizakatum.pbworks.com/f/earths_seasons_worksheet.pdfIn PDF document text
    • http://pajuxuse.pbworks.com/w/file/fetch/144781848/zovanimusepiluredi.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_off0000e92b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92B 5360 bytes
SHA-256: 273b3a0d0cbce81bda2e6b7d1125c65a0ff050c14ce8ce40d094f4620a21b355
font_01_sfnt_off0000fb6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB6A 13176 bytes
SHA-256: 254f42480ed77cd7f56be8b8bed44c725af6c1d5fd5261700d54132bd8692036