Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b3b82917c57af2…

MALICIOUS

PDF

78.8 KB Created: 2021-09-13 01:26:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: efb064a0718db9431d5bb216c3fdd274 SHA-1: 382a6c0a961dd084c50b5fa4d479aae5ff5dc489 SHA-256: 71b3b82917c57af2b5893fb09d4e08f0d312cc025bc06aae7558632d8e81885d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various domains, many of which are flagged as disposable link farms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613644ecf25c6---92245491268.pdf In PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/59659133174.pdfIn PDF document text
    • https://www.acta-mobilier.fr/ckfinder/userfiles/files/42269421167.pdfIn PDF document text
    • http://rideco.hu/upload/file/noxajopez.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16139a16370f50---18031756539.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/mupidexopigajevejeg.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/88048776927.pdfIn PDF document text
    • https://vili-al.com/uploads/wysiwyg/files/masifokuposoki.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/valobizuka.pdfIn PDF document text
    • http://focalthai.com/file_media/file_image/file/68909444719.pdfIn PDF document text
    • http://restavratorstvo.com/ckfinder/userfiles/files/38120184008.pdfIn PDF document text
    • http://nanoscopy.ru/uploads/files/gavewuniwulado.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/42146538080.pdfIn PDF document text
    • http://computerdoki.hu/user/file/wasuwetavolemopegeg.pdfIn PDF document text
    • https://euchebnici.com/img/file/55211775172.pdfIn PDF document text
    • http://imcborivali.org/userfiles/file/56344781051.pdfIn PDF document text
    • https://coffotea.com/uploads/files/202109040522308426.pdfIn PDF document text
    • https://www.nstoplana.rs/ckfinder/userfiles/files/73398693017.pdfIn PDF document text
    • https://khanoomhoteli.com/basefile/khanoomhotelicom/files/46283246272.pdfIn PDF document text
    • http://www.klccpa.com/userfiles/file/In PDF document text
    • https://mobspace.xyz/web/img/podborky/files/52819889400.pdfIn PDF document text
    • http://abwcolley.com/uploads/files/3210826611.pdfIn PDF document text
    • http://lianbang123.com/uploads/files/202109121251286344.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/83220346371.pdfIn PDF document text
    • http://antonio-pelella.eu/userfiles/files/96300179106.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=super+android+17+sagaPDF 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_off0000cbe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e3f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F5 18676 bytes
SHA-256: a6b0bfa1e0c00c2f0222bf19ee70cc1cc794831d4f952b336781eb1eaf89c692
font_02_sfnt_off00011524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11524 10700 bytes
SHA-256: 5886c080331d97b3e63a92f12704a353f77c86fb9fc2ab51421c74f039a948a3