Malicious PDF — malware analysis report

Static analysis result for SHA-256 f36a7235e8fd3a1c…

MALICIOUS

PDF

87.7 KB Created: 2021-07-08 09:33:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: e0c1704fdc54282c00609c81102cafd6 SHA-1: 33a0d21062bcfab569ec75998ee30514e088c182 SHA-256: f36a7235e8fd3a1c02318e60aff0450fe454fa75781f5d613f238614dbb13201
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier with high confidence. It contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://zjqzzx.com/uploadfile/file/2021070221152273499.pdf In PDF document text
    • https://yptea.com/data/fckeditor/files/telujoperuj.pdfIn PDF document text
    • http://www.puhito.hu/uploads/loxodet.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c441a2e41---39786248085.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/nejenisi.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021629131247931.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0a8c2347ee---48359985337.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c91f91f232913953a36a5166ee5ce0a4/86692131271.pdfIn PDF document text
    • http://e-district.org/userfiles/file/91023365768.pdfIn PDF document text
    • http://sarlampa.ru/upload_picture/40695363469.pdfIn PDF document text
    • http://bluefield1966.com/clients/26642/File/duxivaxuvosuzozup.pdfIn PDF document text
    • https://kaptenhoki.com/contents//files/70856480797.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/gp2gipoopph2gbnpit0010qhe6/6042584379.pdfIn PDF document text
    • http://merlegdoktor.hu/tmp/52747735402.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/87c674d8036291195d39d2d420e38459/deguwomixogupel.pdfIn PDF document text
    • http://tcihk.com/userfiles/68497393890.pdfIn PDF document text
    • http://skncn.com/u/files/73606247895.pdfIn PDF document text
    • https://binarbaidequipment.com/public_html/userfiles/file/munaxasel.pdfIn PDF document text
    • http://vistobrasil.net/uploads/file/31310402057.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/mujemufudifexelusuda.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081713f0c9ad---zewawen.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8dc8733756---62805157955.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/440891475c4b93fb66d148015258ca52/18146486380.pdfIn PDF document text
    • http://zge-led.com/luodan/images/userfiles/file/gubiz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=rosa+parks+quotesPDF 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_off0000f535.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF535 16792 bytes
SHA-256: 871f8ed24eeb9eea14bd0bd1c4cf907df24a50828dccca072619b99f52a6fe15
font_01_sfnt_off00012075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12075 10384 bytes
SHA-256: 15e9ecdcf1869f239c056fb1cbe94ac44c4658a0e6ab37faa0c5f955f8176856
font_02_sfnt_off0001382f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1382F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1