Malicious PDF — malware analysis report

Static analysis result for SHA-256 d756c350a240a376…

MALICIOUS

PDF

80.2 KB Created: 2021-09-21 06:17:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 57d99c88d96f5bdda5fb346a928796d7 SHA-1: e6efcc3cfd34c5335430c1356b6e5af1091070e8 SHA-256: d756c350a240a3763fffa3aa77040b66b0022d9ecd3dbfdf350174aa983363a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or are part of link farms on disposable hosting. 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 beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://exteractif.fr/pictures/2/15396913521.pdf In PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/80264968125.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/31438540785.pdfIn PDF document text
    • http://avtosfera28.ru/userfiles/file/78590354653.pdfIn PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/rufal.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132b902abfe8---84745194696.pdfIn PDF document text
    • http://apisicul.com/userfiles/files/92417918369.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16147c2c5432ca---48408236367.pdfIn PDF document text
    • https://manage3.realtourvision.com/rtv/ckfinder/userfiles/images/files/56361083004.pdfIn PDF document text
    • http://globalsublimation.net/uploadfile/files/23228936021.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fafd5e5b7e---95858944325.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/ebce41bea9149ca58a832bbe68796151/56645789645.pdfIn PDF document text
    • http://fratellibeninca.com/images/file/89586021080.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd65072ca6---fexomulavoratasuviwi.pdfIn PDF document text
    • http://avandcie-energy.com/ckfinder/userfiles/files/11219293711.pdfIn PDF document text
    • http://kaies.net/upfiles/210917074014532293iz5ro8.pdfIn PDF document text
    • http://thucancakoihikari.com/luutru/files/rudoxuguxomosovukes.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/kebojetimunelaxezo.pdfIn PDF document text
    • https://sevenhillsgroup.net/ckfinder/userfiles/files/zisebibux.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/57151976190.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/0efe6620ffa912118cfbcbd4ca0ad8d8/25704930797.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/59888477392.pdfIn PDF document text
    • http://magogaralbamoble.com/galeria/files/feramumavunitobirukuni.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/jelipebifitadimel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=creating+bar+graphsPDF 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_off0000d6f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F6 17028 bytes
SHA-256: 75f45909e359f271398ed36f1a5e33cfe18019c7af5a2de12099433042a4ec1f
font_01_sfnt_off00010366.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10366 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B7D 10536 bytes
SHA-256: e2888aa6b599bb5705d6519863cb20500391352c4c043b7743a38016ab213444