Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecaf4ac396c39056…

MALICIOUS

PDF

83.1 KB Created: 2021-09-19 15:13:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 441dfa012687c263028fb3fbee5f5ede SHA-1: 275bda638271b7a6164b949aee5d3df1d67cdfcf SHA-256: ecaf4ac396c39056cfe38acc6900b0589c14eb948932f941ba9ab10ed4785e40
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://dambi.pl/userfiles/file/93643877286.pdf
    • http://studiopol.com/userfiles/files/93528165490.pdf
    • http://wahluenfty.com/userfiles/95505783861.pdf
    • https://emotionalgift.com/ckfinder/userfiles/files/99626494082.pdf
    • http://vipacademy.org/userfiles/file/85151164412.pdf
    • https://subarini.ro/mm/file/94702422219.pdf
    • http://sfipl.in/userfiles/file/93879685005.pdf
    • https://ikincielinmak.com/upload/ckfinder/files/furipulavupotuxaxuzux.pdf
    • http://tlxzkj.com/uploads/file/190506467596.pdf
    • http://gruaszarate.com/ckfinder/userfiles/files/nuzumixozarabudikowan.pdf
    • http://laskod.hu/userfiles/file/ribexepemo.pdf
    • http://idrogastermoclima.it/Utentifile/FCKPage/file/pedapepeluru.pdf
    • http://oio.cn/uploadfiles/files/16408581534.pdf
    • http://epodhajska.eu/UserFiles/File/28642607665.pdf
    • http://cbgnfinance.com/userfiles/file/kodofuvowevasavu.pdf
    • http://bayernglobal.de/userVZ/file/36587110055.pdf
    • http://rebornfair.com/FileData/ckfinder/files/20210901_65E1ACA8AA0DE974.pdf
    • http://chongros.com/userData/board/file/1578993126.pdf
    • http://dataprint.ie/uploads/file/naguzalisosukudikim.pdf
    • http://cafesezony.ru/fck_editor_files/files/tidupodizigeluduxifu.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1613c54406ffa6---gorate.pdf
    • http://kcde.kr/userfiles/file/xisigizijebogefosubeje.pdf
    • http://metall-press.ru/files/43161394387.pdf
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/b2fbfc032d9d2bd2fd8a26b4d273dcfe/ritomufugevujo.pdf
    • https://maribon.net/app/webroot/files/userfiles/files/57636515165.pdf
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16145a95c92cc8---vegoxik.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=friends+season+1+sub
    • 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_off0000df43.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF43 16792 bytes
font_01_sfnt_off0000f755.bin
bfba0529c025021c96427d97fc632cb7abb856029fc06db2eb0c5b377fe9b391
pdf-font-stream PDF embedded font (sfnt) at offset 0xF755 18184 bytes
font_02_sfnt_off0001272c.bin
34a6c258a37b15e1e23b5589b8f797d66aa207229aa483fbb1b14d19fd734c74
pdf-font-stream PDF embedded font (sfnt) at offset 0x1272C 10368 bytes