Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef96def56ecfce78…

MALICIOUS

PDF

81.2 KB Created: 2021-09-22 21:21:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cc3eeb17c3276b043737f26f6bb1304e SHA-1: 549a8a522525e4d7807878f55ce013bcd7b04dda SHA-256: ef96def56ecfce7875f7fbe08701e2b7b06501b58627f2b9bba8c1652c497afb
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' indicates the document is designed to trick users into downloading a password-protected archive, a common tactic to bypass gateway security. The presence of numerous embedded URLs, many pointing to PDF files on various domains, suggests a link farm designed to obscure the true malicious intent and potentially host further stages of an attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161424e943cb3a---molosixobufuxuxuvaxivo.pdf
    • http://vaness-sens.fr/ckfinder/userfiles/files/xalukivosa.pdf
    • https://mlbcsimleague.com/ckfinder/userfiles/files/tusudizulitisewunon.pdf
    • https://www.pharmawell.eu/ckfinder/userfiles/files/22241712744.pdf
    • https://zlato-stribro-investice.com/upload/files/23826566947.pdf
    • http://movitecnic.com/ressource/site-image/files/98755800511.pdf
    • http://harrodsrentacar.com/public_html/userfiles/file/kudivulokozuxuretab.pdf
    • https://marblobathware.com/app/webroot/img/files/mipiginunexalurose.pdf
    • https://multimetrics.com/ckfinder/userfiles/files/66663291470.pdf
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/8cb4e0105f7d1f00ed0cdf4c22af2454/89785520569.pdf
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/28832022406.pdf
    • https://vaynhanh365.net/contents/files/kidoxitudixasapomu.pdf
    • https://marblo.marblobaths.ph/app/webroot/img/files/9773423331.pdf
    • https://pharmawell.eu/ckfinder/userfiles/files/kafezaz.pdf
    • http://xn--sanitrprofi-p8a.ch/fckeditor/editor/images/file/jewatux.pdf
    • http://chothuethietbi.info/img/files/vewijerevipigoni.pdf
    • http://criminisiepartners.it/userfiles/files/48295814517.pdf
    • https://hongdung.vn/ckeditor/images/files/fakuwadavurugisamovu.pdf
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/bivasulumafexikanosaxoten.pdf
    • http://weighlessthisyear.com/ckfinder/userfiles/files/fudilumijuwexasumi.pdf
    • http://debandhelder.nl/ckfinder/userfiles/files/saninavebe.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/695153a77bc753e804ca21db7b9d9a7a/dabademako.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+retrieve+deleted+messages+on+messenger+android
    • 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_off0000d573.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD573 16792 bytes
font_01_sfnt_off0000ed85.bin
b22bb6122b351f066725610220304d5d23485ab5aae24f86f5cf171de042009a
pdf-font-stream PDF embedded font (sfnt) at offset 0xED85 18728 bytes
font_02_sfnt_off00011e15.bin
82bc45ac1ddc001da9f59037d4faa22df9d28761a30bef74915841083b1324b9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E15 10732 bytes