Malicious PDF — malware analysis report

Static analysis result for SHA-256 23db6303e6eec3de…

MALICIOUS

PDF

71.9 KB Created: 2021-06-12 11:10:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: d79cefad5d64542404902cedb5945372 SHA-1: b1b838d1db691a955a482fdf0639647bdb58bc46 SHA-256: 23db6303e6eec3dec8cc1a21d594718640038173a42ad2d0263e660b75906dc3
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://philabc.ru/uplcv?utm_term=group+2+economy+previous+papers+in+telugu PDF link annotation
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/73071f62fcb0b563e9c26f3b05894db0/71079234969.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/gpu2ns4jhrcpi869e4vj8u1pgg/91353133724.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/3b02d55ed06364a4efa580151b8467db/19859071132.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/11714149913.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/6b7f952ca81602c45d69bba7f35e6f74/99904859020.pdfIn PDF document text
    • https://www.sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609452529835e---lowasiwebagiwudebadad.pdfIn PDF document text
    • http://petukmahaaaraj.com/userfiles/file/sobulogiwomulisigobis.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/7854b1ce639dd3e81f1900fb68dac813/dapodoxetox.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/e6vknftld8ruh3rqtftl2slj20/76093586531.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a436303da5b---rezedijiki.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/fdd2c2c460e643d4fc15aedaa63d503d/lojomun.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16078cad05346a---mezad.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB35 5576 bytes
SHA-256: ecd34411c8af9b297325e9863d72cbeb410782251a78b7b3347514fba9e77fb1
font_01_sfnt_off0000ee34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE34 10592 bytes
SHA-256: 5dd9cdafc4e1a70681222d59b2283a95558ade1d732e4c266e7a66845c5296cf