Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9ac3d57a7d5aa92…

MALICIOUS

PDF

89.4 KB Created: 2021-07-19 10:20:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d47ea9c8530733fbf5c26842cd5d2742 SHA-1: fc10707935d7be87997facb6a2643200ffe1173e SHA-256: f9ac3d57a7d5aa9208ca66c4de1d9265b96954d1c34ed8bb3ba05933910c48db
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, suggesting a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, rather than user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://clubesquilacoma.com/uploads/files/5587423642.pdf
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f88ff648ba---mimapominabozetupitagum.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/ffb90b09e5d81a446b08fca0b4659b9e/fediwolobimerepa.pdf
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c942743e6b6---savijililunometuvug.pdf
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/1f2e7618abb81fdaaf0527af35cfa27d/zajaduwomu.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d8a098da0c---28465086147.pdf
    • https://rasorestefano.it/file/patire.pdf
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/f155f566196c27a8289df567308f6062/44748945130.pdf
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/12241058465.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/fe4729d8ce3008ed89b9b848de1f41c3/78076150097.pdf
    • http://keigan-productions.com/clients/863431/File/95947879973.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d88ee8b5372---redeko.pdf
    • https://iwnta.com/userfiles/file/jazejatume.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3e8912a75---62615395142.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddfa5659d8---folivemebamosowodorot.pdf
    • http://stasta.com/userfiles/file/40766859091.pdf
    • http://project-st.ru/userfiles/file/woxejovaxebezuwixofoguj.pdf
    • http://akcjonariusz.com/UserFiles/file/57724820145.pdf
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b0c48950b9f---41806865739.pdf
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce601053d2---76858564300.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba39fc333a---20735290492.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160741531bde7a---71042443353.pdf
    • http://assushop.com/userfiles/assushop.com/file/wetasipube.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+to+fix+xbox+360+controller+joystick
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f8db.bin
82aae43afbef2e5c64f27c7922f7fd633e7f1394a3a15749f2bc5070a347907c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DB 17132 bytes
font_01_sfnt_off0001256f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1256F 16792 bytes
font_02_sfnt_off00013d86.bin
e621d2c59a4b07e194ff000bbd0cf349fcb32917a1f4267263adef0d7941edd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x13D86 11284 bytes