Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d23b704ea5b0edb…

MALICIOUS

PDF

83.6 KB Created: 2021-09-15 21:28:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c2102aaea4d38d507828486db17027ac SHA-1: 8f78b43518eacaf8f16b7cf6e793f6df59819f66 SHA-256: 4d23b704ea5b0edb6e7be20a7ff5b966ddf462812ee4b27f84678257e9050667
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document, potentially leveraging embedded JavaScript for exploitation.

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 https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/kfh9n6vd63ffbifhl1srnmks87/mafogadekofix.pdf In PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613acf0221ac1---wegoxizujitoseruduweso.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/82742129633.pdfIn PDF document text
    • http://prvugkh.ru/uploads/files/88277799855.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/sekunonawefopolikijop.pdfIn PDF document text
    • http://thepducphat.com/upload/files/29880417432.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384ead67cc5---20364631605.pdfIn PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/zujidinuko.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/42846569999.pdfIn PDF document text
    • http://macro-e.com/app/webroot/userfiles/files/89893116826.pdfIn PDF document text
    • http://gemmacapitalgroup.com/foto/file/32623206344.pdfIn PDF document text
    • http://canadianrockies.info/files/file/lavozapimenupanoleremu.pdfIn PDF document text
    • http://apart1day.ru/file/85553428351.pdfIn PDF document text
    • http://rheumatology.institute/upload/content/file/kirebamewomixumopaxi.pdfIn PDF document text
    • https://kompaspt2.com/contents/files/83527595430.pdfIn PDF document text
    • http://glttek.com/userfiles/file/27168473407.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/redelexozifiladeruna.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109051622427733.pdfIn PDF document text
    • https://vilnius.cvzona.lt/resources/img/files/xedexutavo.pdfIn PDF document text
    • https://ntct.dz/ckfinder/userfiles/files/wazuvipu.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/2fca65e44d055c10c0d76a74ec10b734/11632231726.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/widamipoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=screen+size+of+a31PDF 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_off0000de72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE72 10544 bytes
SHA-256: 3a53f46001f665f7a74333a7ba0ffc2d3e147c5e1ac24b41df8956612042fe20
font_01_sfnt_off0000f6a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A7 19108 bytes
SHA-256: 140fe5c7ad9ad3efa705d731c13905bff489df942cc9663c39b2315c2cbcc6c1
font_02_sfnt_off000128e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1