Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f6f71d9cdfedd4…

MALICIOUS

PDF

83.1 KB Created: 2021-09-18 21:49:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: caf06f70c18f191807ce369532349094 SHA-1: b687dba0cc79e17726c8b7a173bd2fa85d6cf8aa SHA-256: 81f6f71d9cdfedd48d9dd79052d1c1cd178e6c1b72f69bcd176671f576e00345
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external links, many of which point to compromised WordPress uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded URLs and the PDF_URI heuristic indicate an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://queure.ru/uplcv?utm_term=omnisphere+2+full+download PDF link annotation
    • http://jngf.cn/files/file/vukopigijejedefuxipigizuv.pdfIn PDF document text
    • http://baove24h.info/upload/files/79022434698.pdfIn PDF document text
    • https://nmcs.ca/userfiles/files/nurigudakobefenezuz.pdfIn PDF document text
    • https://chataigne-cevennes.fr/imgs/files/53613101161.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/53401356168.pdfIn PDF document text
    • http://marcobernini.it/userfiles/files/87193227079.pdfIn PDF document text
    • http://gmart-express.com/demo/uploadpic/file/vifasumuluses.pdfIn PDF document text
    • https://ist-lb1.istanajp.com/contents/files/54883433449.pdfIn PDF document text
    • http://sintellect.ru/Repository/file/45469540007.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/207d17a9435fe48613623a0955c4e418/soluxipa.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/finajokax.pdfIn PDF document text
    • https://groupburuemas2.com/contents/files/junesewisubigaz.pdfIn PDF document text
    • http://www.la-rocca.pl/app/webroot/files/files/29584307224.pdfIn PDF document text
    • http://ccsl.asia/files/92832000734.pdfIn PDF document text
    • https://coil.hk/upload/files/vibixot.pdfIn PDF document text
    • https://baglab.pl/galeria/file/65436175010.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/61172820219.pdfIn PDF document text
    • http://www.rify.us/cms-uploads/files/4301515343.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/ccdtsjicfr2hin0ioiepcvar07/86945562860.pdfIn PDF document text
    • http://kosmonautika.ee/ckfinder/userfiles/files/jotufefobuperat.pdfIn PDF document text
    • https://tlproduct.com/userfiles/file/vufasuwam.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161381baf6155d---fumigodapalitadax.pdfIn PDF document text
    • http://bigcool.net/webroot/img/files/nosemanab.pdfIn PDF document text
    • https://scout-educationguide.com/userfiles/file/zexedemedividuxi.pdfIn PDF document text
    • http://krallarintavugu.com/upload/file/57363131195.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://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_off0000e072.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE072 10996 bytes
SHA-256: 752b78ae15c79bd254374ac9acde35ee8da591e65338a815717d5bfeadbb7e33
font_01_sfnt_off0000f9d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000111eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111EB 17376 bytes
SHA-256: 0af518fe90bb4af37ecdc111728eca95599636f3859620ec03a0741c03f6afc5