Malicious PDF — malware analysis report

Static analysis result for SHA-256 353e13433b4704df…

MALICIOUS

PDF

70.9 KB Created: 2021-09-27 13:55:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f9d8e46a9314b8674629bc15db09cc85 SHA-1: ae8706f55104fd45a57607909ded76b85ffe10a5 SHA-256: 353e13433b4704dfb9cc37f2a5f81abf1680c72f9401669fb90f5110dd747726
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO poisoning campaign. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://aelma.com/sites/default/userfiles/file/wajisaf.pdf In PDF document text
    • https://banerjeetourspecial.in/ckfinder/userfiles/files/bubebijig.pdfIn PDF document text
    • https://haruhonpo.com/upload/haruhonpo/files/97466981723.pdfIn PDF document text
    • https://dienlanhhonganh.com/images/pic/file/minuba.pdfIn PDF document text
    • https://coombs.gocascadia.com/images/cms/file/darazonivodorumiwoz.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/63566347962.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021090715590119.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147fd730929f---vizegebuxoxivudogunuf.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/xotavejuzaxetakow.pdfIn PDF document text
    • https://ckv-siemreap.org/ckfinder/userfiles/files/8426650725.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/d7c4c9e3aa0a3efe89eb527b66b99d0d/17907122485.pdfIn PDF document text
    • http://lammermoor.net/imagenes/file/beguzativufadot.pdfIn PDF document text
    • http://saeronbio.com/userData/board/file/30767584376.pdfIn PDF document text
    • http://hodori247.com/uploads/files/32477970063.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/vibobagizoralavibepe.pdfIn PDF document text
    • http://redactron.com/userfiles/file/panoxozogi.pdfIn PDF document text
    • http://trumoi-khutrung.com/upload/files/90500500092.pdfIn PDF document text
    • https://ruiguoex.com/upfile/files/2021/09/04/bojonudufozono.pdfIn PDF document text
    • https://www.truckersplantparts.co.uk/ckfinder/userfiles/files/gufuzile.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/dupunotalofenapixoxutafi.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614f038d1ed34---vinafokamajenuxebov.pdfIn PDF document text
    • http://karpatskiles.ru/store/file/64106822090.pdfIn PDF document text
    • http://atanasijornet.net/uploads/ckfinder/files/34316458907.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/tivuvevowadakapa.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/62732571543.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=kingroot+for+android+8.1PDF 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_off0000b459.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB459 10500 bytes
SHA-256: 4ab73f056b09b7f73958cd8aae2d6957d7276f74528d719b8cc9a64422ae8877
font_01_sfnt_off0000cc29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC29 16488 bytes
SHA-256: 726b2a250b0ec3398346f25e8b29c55c799f24b73b65e31d835a7c0b05790bde
font_02_sfnt_off0000f597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF597 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1