Malicious PDF — malware analysis report

Static analysis result for SHA-256 e18f3719da328dfa…

MALICIOUS

PDF

81.7 KB Created: 2021-09-04 13:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 68d11dc4af932ea63798822b82de460f SHA-1: cb76cdd6b9136f89f8b2c81cd0819d9a984d3d21 SHA-256: e18f3719da328dfaa8007b5dd77934454f8df3e3947bf18f132b70a8a1845074
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose.

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://cu-mbc.com/ckfinder/userfiles/files/29800898100.pdf In PDF document text
    • https://nevisnews.com/userfiles/pebotitofaruwide.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/kegibuz.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/q1uehufl4ievo7ma0upqp9shbn/91327925512.pdfIn PDF document text
    • https://inncredel.com/uploads/56847688614.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ec3edbb5435---94764198640.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/gokinixusewisago.pdfIn PDF document text
    • http://nenorm.com/files/files/30542818638.pdfIn PDF document text
    • http://motocams.cz/ckfinder/userfiles/files/56127913658.pdfIn PDF document text
    • https://ienter.bg/files/wokakobibawapekuzegapogog.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/v1t78cbvrppj1fqe6gm46s3v7p/dakopepepabigerokogubotev.pdfIn PDF document text
    • http://bvsaigonbinhduong.vn/uploads/files/zupixujupibele.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082635834b33---89696459710.pdfIn PDF document text
    • http://93564497.com/userfiles/jepetebufefafu.pdfIn PDF document text
    • https://ozmutludokum.com/userfiles/file/95717779765.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/ribegitipofujogutelikiri.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/kukatifigusitezuj.pdfIn PDF document text
    • http://agrion.org/upload/fichier/pabobewudufopasosaw.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/c1a7eb5b8ba83cd98a6363dfe1aba655/92583214388.pdfIn PDF document text
    • http://marcus-1.com/FileData/ckfinder/files/20210624_43637AAD4512C44E.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210504222937100.pdfIn PDF document text
    • https://xenang-mitsubishi.com/fckupload/file/88528840825.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=environmental+engineering+and+safety+notes+pdfPDF 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_off0000d783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD783 18212 bytes
SHA-256: c41b9518e5097c94c7601197f856c262d3ad566bfe3cba718af815f21427adaa
font_01_sfnt_off00010722.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10722 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F39 11004 bytes
SHA-256: 3a60589fcec788c467af096c55cec422175d0e99970921b24fc481ed77656c1d