Malicious PDF — malware analysis report

Static analysis result for SHA-256 35ceb63fa33fa84f…

MALICIOUS

PDF

81.5 KB Created: 2021-09-16 16:24:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 419e4e50e1bdee7dc7786b7a7ed2d52b SHA-1: a6510fbbbe51197a7863f6447cdda37759482e2f SHA-256: 35ceb63fa33fa84f77e4ee1c02779005c991a67bdae1cdee785d46b7e17a04d7
182 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, some of which are part of a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to trick users into downloading a secondary payload. The presence of a visual download button further supports this lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://hydratrend.com/application/third_party/ckfinder/userfiles/files/10163012266.pdf
    • http://doubler-son-capital.com/photos/files/67392007979.pdf
    • https://projetounificado.com/uploads/files/78609837417.pdf
    • http://ecohost.ru/pics/images/file/talijujesapobawib.pdf
    • https://tennis94.fr/img/pics/files/padixujeretinirireso.pdf
    • https://detskeihriska.eu/ckfinder/userfiles/files/88952728889.pdf
    • https://prcomponents.com/ckfinder/userfiles/files/pukipazibisofax.pdf
    • http://yingtailong.com/upload/file/210907141723980720r1otv1rej1we.pdf
    • http://aktifbant.com/resimler/files/63040638039.pdf
    • http://studiotecnicopetrillo.eu/userfiles/files/xewifu.pdf
    • http://vagtteam.com/userfiles/Files/16120968103.pdf
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/1tmdkgpcmd3u7ltda9tee8sqjs/furodivamuriwaxiwos.pdf
    • http://rjt1.org/upload/files/89621269785.pdf
    • http://self119.net/upload/userfiles/2021/09/files/210906155357.pdf
    • http://bananamusic.tw/uploads/files/202109101255447885.pdf
    • http://dfanchem.com/upload/files/malosazudutaka.pdf
    • https://hophamthaibinh.com/upload/files/32852418891.pdf
    • http://wcsps.com.tw/ckfinder/userfiles/files/nitemosefilapilowufopes.pdf
    • https://3rproject.eu/ckfinder/userfiles/files/liminiwaxegawanijofirati.pdf
    • https://nguyenthelong.net/userfiles/files/delukuketago.pdf
    • http://nutranghongngoc.com/media/ftp/file/rifuvixopipop.pdf
    • http://tw-echen.com/uploads/files/202109130854073954.pdf
    • http://arredamenticucinesiciliane.it/userfiles/files/82845199704.pdf
    • http://www.uc-kushiro.net/images/library/File/23908804707.pdf
    • http://www.erealitysolutions.com/tennisontario/assets/appsadmin/js/ckfinder/userfiles/files/mokavajexewozusupoxi.pdf
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/7003445947.pdf
    • http://techniq.ae/admin/uploadfiles/file/83120369113.pdf
    • http://rjt1.org/
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=garena+support+base+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1d5.bin
cc242aa39b2028d60031d2c635f717de43e25a603345b94a0e757bc0a7902c20
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D5 10480 bytes
font_01_sfnt_off0000e99a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE99A 16792 bytes
font_02_sfnt_off000101ac.bin
fd686eb530d6c1e7ca7b3c6a65e1bdb87d8bd3fb48a49c4b4b913727a195bf18
pdf-font-stream PDF embedded font (sfnt) at offset 0x101AC 20740 bytes