Malicious PDF — malware analysis report

Static analysis result for SHA-256 d40cc8ad2d3bc198…

MALICIOUS

PDF

85.6 KB Created: 2021-08-15 14:53:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 85796401338a27da70c6e77961345aff SHA-1: fec8824c3a5864977c04bd2c6647fd819d449c98 SHA-256: d40cc8ad2d3bc1983a08d1617867fd884ce4f4b83e813f89aa9b80f4480f92cb
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic firings are sufficient for a high-confidence assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16084785431b5c---60930580891.pdf In PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/4764809201.pdfIn PDF document text
    • http://koronowskasm.pl/file/66214029134.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/bd36d439dc0b26498984f6d552141fca/wimugixilod.pdfIn PDF document text
    • http://kleinschaden.expert/userfiles/file/pamisoja.pdfIn PDF document text
    • http://a-mega.ua/images/uploads/file/kodanunediwirewasesojev.pdfIn PDF document text
    • https://kaimano.it/file/volekifufizewixalubowagi.pdfIn PDF document text
    • http://taperagi.com/contents//files/68733831753.pdfIn PDF document text
    • http://jingyilin.org/uploads/file/difibukogexowediwakukolux.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160d0223712454---36178235773.pdfIn PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/44462e74a8216d5ee5624930c3d51005/fizofadujifamokidakevo.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073ebcd502a1---zorijepop.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/dofatogajusobak.pdfIn PDF document text
    • http://asremajazi.com/uploads/files/kugoriso.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/hekjgto0k6n41r6g8rattkg3j4/pulewopivilavedelosamed.pdfIn PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/51403977249.pdfIn PDF document text
    • http://hfnhsw.com/upload/files/dipidudumuraminod.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16075320555022---todukanaxivak.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca0ee1ccb90---56457218557.pdfIn PDF document text
    • http://win-sonic.com/kida2018/ck_imgs/files/dotofutiwozutasasiz.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/b553a1b7466a00113887f7ffcc227e5f/85366518483.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/mimilizesoziposazukafuv.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/jt5ug1amfc9dgiljvjqdh3o6ep/sowurizemefedugu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=what+is+the+best+video+calling+app+for+androidPDF 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_off0000e771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE771 11100 bytes
SHA-256: 3ec4a5c6f7f99e72d02ac300f22b6329e75aa5feb4499eba3f0a69ca1affea7e
font_01_sfnt_off000100d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000118e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118E9 17020 bytes
SHA-256: 01bc9aff23126448b75fbb91f91a484d19e274eab56765f00489ead774d5705c