Malicious PDF — malware analysis report

Static analysis result for SHA-256 90e8c4d3cbd52cf4…

MALICIOUS

PDF

76.4 KB Created: 2021-09-21 02:46:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 61ca3c7579cf7c043baba00f8c21b32f SHA-1: 08818bd117ee1585bf46216efd2da4915003b76b SHA-256: 90e8c4d3cbd52cf49cc92dcc8e72c0b5732c882647df3925a228b3663e90b615
166 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The 'Browser extension / update installation lure' heuristic indicates the document's content is designed to trick users into installing malicious software. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it is part of a phishing campaign, likely leading to the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://medvor.ru/uplcv?utm_term=my+cv+is+attached+to+this+email PDF link annotation
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f133e35ef4---9846087361.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/70631346879.pdfIn PDF document text
    • http://www.shjkyq.com/up_files/FCK/file/nelivemuxanoginebali.pdfIn PDF document text
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/92997408094.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/tubujuduwomupid.pdfIn PDF document text
    • http://mamaskitchenorder.com/uploads/files/9211607868.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/95586550604.pdfIn PDF document text
    • http://digivideos.net/ckfinder/userfiles/files/44097161755.pdfIn PDF document text
    • https://parlagame.net/calisma2/files/uploads/dumemu.pdfIn PDF document text
    • http://icaalliance.org/filespath/files/20210917022228.pdfIn PDF document text
    • http://cjcounsel.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/51323660190.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/zolimok.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/23079749156.pdfIn PDF document text
    • http://srtprogetti.eu/userfiles/files/fewazixa.pdfIn PDF document text
    • https://5udua.com/contents/files/65987300731.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/fuwowasolabeja.pdfIn PDF document text
    • https://sahodayabbsr.com/test/fckeditor/file/52798988841.pdfIn PDF document text
    • http://numere-mopede.ro/mm/file/fegudexikupiradaxepidubip.pdfIn PDF document text
    • http://proreferee.ru/uploads/ckfinder/files/wukosevika.pdfIn PDF document text
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/54307626399.pdfIn PDF document text
    • http://villapellegrino.it/userfiles/files/13281020651.pdfIn PDF document text
    • http://xn--h49al71atridzo.com/userData/board/file/rojoxin.pdfIn PDF document text
    • https://ciar.vn/uploads/image/files/20550692849.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_off0000c983.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC983 16400 bytes
SHA-256: 1945543e3e05248bc1a7c6789b0a1cb08609816b887df5d611e742965bcdd324
font_01_sfnt_off0000f3a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BBB 10604 bytes
SHA-256: acd47ea248600b007dfbe3a3f08daf48c2ae1eebac606c9661ba24e23e226ea1