Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef15e7857881f559…

MALICIOUS

PDF

84.5 KB Created: 2021-09-10 12:48:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e8bf348072b26d9a3df451c16c48f7ed SHA-1: 1b0696d78af851c1234730190514081835eba9e7 SHA-256: ef15e7857881f559068eecb326ead3acbe201d49a51539d9bbbb2c0defc859db
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. The presence of numerous external URIs, many pointing to PDF files on disposable hosting, strongly suggests a phishing or malware distribution campaign. The ML classifier and ClamAV detection further confirm its malicious nature, likely as a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 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://sanaspinler.com/calisma2/files/uploads/betikanujalusekinitoxe.pdf In PDF document text
    • https://rimi.sk/userfiles/file/wegavola.pdfIn PDF document text
    • https://tidymoney.com/ckfinder/userfiles/files/gokakovekigunimatak.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1630520053.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9deac65e7---pivipajen.pdfIn PDF document text
    • http://print-printonline.com/ckfinder/userfiles/files/70471544652.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/tanulukirazodo.pdfIn PDF document text
    • http://lohoithaiduong.com/uploads/files/fonufinupofabamudewuxoko.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/kelemumopodel.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/6602503084.pdfIn PDF document text
    • http://fuyu.010bi.com/ckfinder/userfiles/files/ratekurujaw.pdfIn PDF document text
    • http://tufaghanafc.com/js/ckfinder/userfiles/files/68682446463.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/tigofugikexaz.pdfIn PDF document text
    • http://www.jokilaaksonratsastajat.fi/file/tivubowalewizabewapuma.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161340aa673ecc---83755616967.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/wonijiriludevoranatukepas.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/46248974266.pdfIn PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/12648961352.pdfIn PDF document text
    • https://giolog.biz/images/bulk_images/files/95417985057.pdfIn PDF document text
    • https://beauty-full.ru/uploads/files/56138818940.pdfIn PDF document text
    • http://ensky-chemical.com/upload/files/binaj.pdfIn PDF document text
    • https://hagabb.ro/ckfinder/userfiles/files/55125197704.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/1613342b73ce09---1051053633.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+delete+credit+card+from+androidPDF 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_off0000e48e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE48E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fca5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA5 10548 bytes
SHA-256: e80d4e321c25d96defdf49fcebe5cefce1c11fa878480516fbfff94d4df2c729
font_02_sfnt_off0001149f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1149F 18248 bytes
SHA-256: fc5e8ec60f71f280a0904b78c6db22cf6f47cae87036c91b6852a64d81a112e3