Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8f670663448f318…

MALICIOUS

PDF

84.9 KB Created: 2021-09-21 03:01:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c065d626628575548ef4f4839d6b47c2 SHA-1: 2a9646803dc9ce637b9c6c6b748129e4853fd54e SHA-256: a8f670663448f31847d1a5aa3e9fc8955664b741cdb48bf6dd8fe295c6854f0b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with many pointing to suspicious domains and file names, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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 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://www.larche-de-jules.fr/ckfinder/userfiles/files/pamaxenibeko.pdf In PDF document text
    • http://studio70.eu/userfiles/files/41130411658.pdfIn PDF document text
    • https://kcss.hu/korosi/userfiles/file/munamukoxujorerenedobu.pdfIn PDF document text
    • http://heathrowairporttaxi.website/userfiles/file/50491822402.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210906030053.pdfIn PDF document text
    • https://swaarm.de/app/webroot/upload/files/29707731585.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/9988406386.pdfIn PDF document text
    • https://democv.associasuite.com/imagenes/contenidos/files/27370670445.pdfIn PDF document text
    • https://ans5680.preneed91.com/upload/files/83243886272.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613742a8497e3---mutumoze.pdfIn PDF document text
    • http://staresecurity.com/userfiles/file/5253410824.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4da4aa21a---pivawikanezod.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/kizerigoduwojurove.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/rijato.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/nijirolovavavidotaxedugaf.pdfIn PDF document text
    • http://healthywithhart.com/res/file/pikuvebobusaf.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/xipupukanipumabo.pdfIn PDF document text
    • http://tpt.taipei/asset/uploads/files/bifovokosutifo.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/gakojowevegolej.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/31459902394.pdfIn PDF document text
    • http://dominopark.pl/public/upload/ckfinder/userfiles/files/rixuzukajamidawalarilu.pdfIn PDF document text
    • http://benly-carson.com/product/files/winaluwarinoraboxejixugug.pdfIn PDF document text
    • https://csmgh.net/pevron/www/img/file/57572789644.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/zefolixekivorubux.pdfIn PDF document text
    • https://norservis.com/files/files/powuzepuxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=sopcast+android+tvPDF 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_off0000e1f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F4 19760 bytes
SHA-256: 6ee0dd7b9fd6b385427abf57d2d070fa88b434bfbf72b3b08211176533fe9c89
font_01_sfnt_off000115e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012dff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DFF 10472 bytes
SHA-256: 6c5c0b5ba9388ae1fd18bda7621a4c995f4cae9e94178107c6bf8e50fb8997ca