Malicious PDF — malware analysis report

Static analysis result for SHA-256 76a712e40ef766cf…

MALICIOUS

PDF

93.9 KB Created: 2021-07-05 06:37:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 4931cb3b8de4e77583fb323513ba7f8c SHA-1: 4832af3ba086aa0030313d11c22c7cd1571a2bd7 SHA-256: 76a712e40ef766cfface8fec12c4b8bfacd86f0b36b52c4a4d888d36940f294d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to manipulate search engine results or redirect users to malicious sites. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://arrayamed.com/userfiles/file/jebulepetufomezumenadex.pdf In PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/99075811192.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/lofafiwokekolanujiw.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/d3663bb2af90f5e36f6fe3afb46c1bb6/57510621379.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/voretobarenefatadoxibuk.pdfIn PDF document text
    • https://locoffice.ru/userfiles/file/76188614126.pdfIn PDF document text
    • https://path.mn/userfiles/files/24474552661.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d24976df3f---sidunuwebozadutojena.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/6befdb4c5d09924ac183dc840b1b245f/jexono.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095eb881c8ca---zebezitazimomise.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160beb2a240e23---74045890105.pdfIn PDF document text
    • http://asiancfea.org/userfiles/file/juzosexi.pdfIn PDF document text
    • https://dm288.rs/slicice/file/tarawavupisaz.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/71403439186.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a249241ec26---pisidakivonepenuragitibo.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/hhff5cb36f3ulf4621j9rrh72r/nikixer.pdfIn PDF document text
    • http://mujuerp.com/uploads/ckeditor/files/20210615162546.pdfIn PDF document text
    • http://dermaktif.com/imgup/file/vikegulo.pdfIn PDF document text
    • http://hutergroup.de/userfiles/file/pozumuveximabapuzupalose.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16075dba7e09d7---bovixul.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbefbcd117c---rewoxexojiludajusatixom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=the+longest+insultPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010b80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B80 17920 bytes
SHA-256: f2810810fb7d102c126b7891e161eb9398014de30ec36140c94fb801e2706312
font_01_sfnt_off00013aa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AA7 10188 bytes
SHA-256: cdde671864c6384181afd7cfa84b45eb6b62ed08f84301c556fbc742e7b4ef1d
font_02_sfnt_off00015174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15174 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1