Malicious PDF — malware analysis report

Static analysis result for SHA-256 efb9ae10da8dfa9c…

MALICIOUS

PDF

78.1 KB Created: 2021-09-14 10:18:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c045333c1c25f3c2f7c0a804e482c632 SHA-1: 2d16ac5b977b6f3d587d9416512b0da713c5eb5f SHA-256: efb9ae10da8dfa9c0b7b0b7107dce70220a299deca3fe3c9d5fff609f2c78454
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URIs, many of which point to disposable or unknown hosting, suggesting a link farm designed to distribute malicious content or phish for information. The document body is heavily obfuscated and unreadable, but the presence of numerous external links is the primary indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://aligokdemir.com/resimler/files/luxefegibejogironotubi.pdf In PDF document text
    • https://betenenergy.com/sites/default/files/file/20016556792.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/37847544366.pdfIn PDF document text
    • http://styrexon.cz/userfiles/file/dupak.pdfIn PDF document text
    • https://butzbacher.turnpoint.jo/app/webroot/upload/files/laweb.pdfIn PDF document text
    • http://snnet.kr/board_pds/fckeditor/2021/09/file/46842834471.pdfIn PDF document text
    • http://cuacuontoanthang.com/media/file/jukurajudavadoliketubewob.pdfIn PDF document text
    • https://netlandschool.cl/files/numikirewojebuborebevakob.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4249b199c---13802922507.pdfIn PDF document text
    • https://ms1oke.com/contents/files/rexiwobuvup.pdfIn PDF document text
    • http://dmkert.hu/files/file/jowuto.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021090213573070554.pdfIn PDF document text
    • http://bienbao.net/uploads/files/35179804061.pdfIn PDF document text
    • http://congluc.com/upload/files/19501227074.pdfIn PDF document text
    • https://merohamro.com/ckfinder/userfiles/files/gemopijugeromuzafigumis.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/46315123944.pdfIn PDF document text
    • http://kxqcgs.com/filespath/files/20210913082907.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613432a8e9018---zafuxozuwifanifimupanevu.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/koxegexaba.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/zibulefanubividop.pdfIn PDF document text
    • https://maisonforville.be/documents/file/26090444210.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/87271954776.pdfIn PDF document text
    • https://pesonabali.dswip.com/ci/userfiles/files/lodaranenesanowi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=mtk+engineering+mode+pro+apkPDF 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_off0000cdbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDBD 17508 bytes
SHA-256: 00a8b4cbedb64d5150b5511d7b5d3bf88c1343ffa7b4f2640bb061e1bc6ddd7c
font_01_sfnt_off0000fad9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD9 10604 bytes
SHA-256: 9bfc08c3f4eb82143c2951a18ecc3e74461b653f170cbca841f28d3feecf93fd
font_02_sfnt_off000112e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1