Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5d86e9ef085bf0…

MALICIOUS

PDF

69.9 KB Created: 2021-09-25 03:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d90fd38c86ad3e3547e230d148b7b7de SHA-1: 991b052574fbc43e11a18a9f1e3c91915544ecd5 SHA-256: cf5d86e9ef085bf04e01fcb9f3a4f8c75aecd39fb3e6a3e28d12ac0ba3eced2c
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a link farm pointing to multiple PDF files hosted on various domains, some of which are identified as compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading further malware or engaging in phishing. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://groupunsur3.com/contents/files/45101853799.pdf In PDF document text
    • https://alves.bg/ckfinder/userfiles/files/vigaxidu.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614e50890b95f---63340725273.pdfIn PDF document text
    • http://zhongyuemedia.com/filespath/files/20210919000100.pdfIn PDF document text
    • https://larrialdiak.es/files/galeria/files/22439116264.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/bisas.pdfIn PDF document text
    • http://pinedafoundation.org/imageuploads/file/61840832176.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/velagorodejuba.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/30573611394.pdfIn PDF document text
    • https://greenbins.ca/ckfinder/userfiles/files/luwemubupawifonogi.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/vevoleritipagejijo.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/kukimudatofefibewuxarinam.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/pifori.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/nafigile.pdfIn PDF document text
    • https://rais.bg/uploads/file/28093925674.pdfIn PDF document text
    • https://lecourbe.dk/userfiles/file/17504604651.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/e1d2bf6abd3bd434a59c2848e1f9e9aa/bubuwabuvikizi.pdfIn PDF document text
    • https://sitarasign.ir/data/file/kididobopoguzanixiwo.pdfIn PDF document text
    • http://pizzeriadevita.it/userfiles/files/ziwakudegorigu.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0bf9dbee0---kanidanekozanapop.pdfIn PDF document text
    • https://moraure.net/js/ckfinder/userfiles/files/79545227342.pdfIn PDF document text
    • https://songod.vn/uploads/image/files/padagataliwed.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=download+inshot+pro+apk+free+for+pcPDF 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_off0000afc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c7d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7D3 15904 bytes
SHA-256: c9fa0a6f0b3c83d382f9e73f256a581932402ad8ba54b8c29625aa85ada18514
font_02_sfnt_off0000f08d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF08D 10896 bytes
SHA-256: fcc4fe928df7b1b5165a8cd9140fe50b58f6efe92d0b22e8095f89ccc3241a20