Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8b6e834f6cf8b77…

MALICIOUS

PDF

83.0 KB Created: 2021-10-11 09:35:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 31946037713cb3dffb964a249eeff405 SHA-1: e8f86e47df03a6654f29b3bb7b4ab9be5ef908f2 SHA-256: a8b6e834f6cf8b7792c90287ef588bddc098fb464d4ab6d253fc271bd469905c
156 Risk Score

Malware Insights

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

The PDF contains a link farm with multiple distinct hosts, a common technique for phishing or distributing malware. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. The embedded URLs suggest an attempt to redirect the user to external, potentially compromised, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://xn--80affcyoc0ac1f6a.xn--p1ai/admin/modules/ckeditor/ckfinder/userfiles/files/fadukadasimusujer.pdf In PDF document text
    • https://techinnsrl.com/writable/public/userfiles/file/13404930772.pdfIn PDF document text
    • http://plkorea77.com/ckupload/files/vixifabozeso.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615d73641cc91.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210920015934.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/zifofisid.pdfIn PDF document text
    • https://38e5bbdfe8be.gdziezjesc.info/userfiles/file/jawusipakezogibir.pdfIn PDF document text
    • http://manu-transport.com/documents/file/8233710017.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/rorejikogapudaloxebevefos.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/gozebewogizoziziwupanukib.pdfIn PDF document text
    • http://vodnik48.ru/content/file/pesoxafodejalutoxepadob.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161515d7133d44---81194563499.pdfIn PDF document text
    • http://roosprommenschenckelfoundation.nl/userfiles/file/41669266322.pdfIn PDF document text
    • http://aqgwegfjdlk.handyfriendship.com/upload/files/85958972738.pdfIn PDF document text
    • https://euronuts2009.ge/files/files/16982466889.pdfIn PDF document text
    • http://connect-event.fr/ckfinder/userfiles/files/32094933590.pdfIn PDF document text
    • http://caffepontoni.com/uploads/file/belulumudisufekojagifu.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/9092859aaca47665b0b6ed096bfa0eb6/medefonofabav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=deadly+heat+wavePDF 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_off0000de40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE40 19476 bytes
SHA-256: ce9582873560ab4ab4ed61aa9eee71431a9f0d77eec258545031011512acdd13
font_01_sfnt_off0001107f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1107F 10028 bytes
SHA-256: 1fab39261d4c3caeb14f9ab93a1c087862bbc093f03c92c78958950726ee258a
font_02_sfnt_off000126f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1