Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b1235c640bb08bc…

MALICIOUS

PDF

85.4 KB Created: 2021-08-06 11:50:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 39bdd7956b4ba93d9ea3d242a7606d32 SHA-1: a225ae59e039868b01374ab03580dfc80982c644 SHA-256: 3b1235c640bb08bc2181e621a7bda0fe78d007a50663bba97bac43ef1ecc4c33
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 uploads, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://sanga.asia/userData/board/file/1300711092.pdf In PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f740fd3074---pukojijuloxusadorawenobav.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087f99b6f629---kutiva.pdfIn PDF document text
    • http://esistore.de/userfiles/file/tojunogemefez.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c14861a4b4---93817925306.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/petorurotativozivolejiso.pdfIn PDF document text
    • http://karmand24.ir/basefile/ehotel724ir/files/8149483295.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b7896eedb---68481383744.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/d5b288722999f308db2ddf34003d0aab/59808056879.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/30211392341.pdfIn PDF document text
    • http://kco.su/userfiles/file/julavoxiwozuladuled.pdfIn PDF document text
    • https://praward.tw/wp-content/plugins/super-forms/uploads/php/files/2be32ba78c58830fa97ad81779221325/31137237401.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/36913706301.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/vetovesiwerexizuzekigi.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210718141947.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/tj6m5v0qcrf8hkhp7ulh77lg7c/40009611253.pdfIn PDF document text
    • http://hindel-relax.ch/ckfinder/userfiles/files/suxixejaziwetikonowavu.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/nizaben.pdfIn PDF document text
    • http://meyanko.com/userfiles/file///67369046889.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=san+francisco+muni+n-judah+routePDF 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_off0000e801.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE801 11032 bytes
SHA-256: 2f08945508daad363108610ef57e2ecf22f4008649f0ed7a947f0b38ace2232e
font_01_sfnt_off00010180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10180 17532 bytes
SHA-256: 3997b6a19154d0c27e23490579ff2bf31bad7743f7894c9b222883881f479fc1
font_02_sfnt_off00012fda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FDA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1