Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fb1558c502e0fa2…

MALICIOUS

PDF

66.2 KB Created: 2021-10-02 22:17:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f3f476887c9d18733886c7464d71be11 SHA-1: 4da3b042c3d768232f0b64f5c3c9f2353dc01367 SHA-256: 3fb1558c502e0fa278ddc0471be787ea1f3ccfac5705e2ce24c06f5e1ba68dc2
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with heuristics indicating embedded JavaScript and a high density of external links. The embedded links, such as https://queure.ru/uplcv?utm_term=adult+children+of+emotionally+immature+parents+free+pdf, suggest a lure to external content, likely for phishing or malware delivery. The presence of embedded JavaScript further supports the potential for malicious actions within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8010

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://queure.ru/uplcv?utm_term=adult+children+of+emotionally+immature+parents+free+pdf
    • https://egyediajandekotletek.hu/mvc/userfiles/file/17478174291.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f795bea554---bezuriruweranive.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/t8tc5h44f3bjtlo5jpqc3u4nu5/33293171635.pdf
    • http://pressvaluation.net/FCKeditor/editor/filemanager/connectors/userfiles/file/28164731015.pdf
    • http://andrenickels.de/ckfinder/userfiles/files/xabibusaruvudusuj.pdf
    • https://soyana.de/js/ckfinder/userfiles/files/lexotejesixifog.pdf
    • http://sartor.ru/upload/files/47927359895.pdf
    • http://www.electricman.in/demo/frontend/web/uploads/files/xalawakof.pdf
    • http://isotope3.pm-ural.com/uploads/files/xoniwazidekatexixuv.pdf
    • http://denprokhorov.ru/images/file/22894965830.pdf
    • http://morakothotel.com/file_media/file_image/file/35637684143.pdf
    • http://kruengrangthai.com/files/files/lilatobumovumo.pdf
    • https://aildf.in/userfiles/file/lojif.pdf
    • https://rajakeempat.com/contents/files/xafalubugugakiw.pdf
    • http://cp-tournament.org/ckfinder/userfiles/files/11101399058.pdf
    • https://hebatkeren88.com/contents/files/nukagomegu.pdf
    • http://bigcool.net/webroot/img/files/jewifejuw.pdf
    • http://chelseafoodmart.com/uploads/files/bopirazijevopu.pdf
    • https://1877painters.com/FCKeditor/file/9472862118.pdf
    • https://bya-ingenieria.com/ckfinder/userfiles/files/wovepodibonulexox.pdf
    • https://virtrade.gr/userfiles_lybo/file/gowibosuwox.pdf
    • http://yugreat.com/filespath/files/20210921144319.pdf
    • http://cluster006.ovh.net/~greeters/be/ckfinder/userfiles/files/48161784959.pdf
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/pevamuzigolatezeredef.pdf
    • 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_off0000b230.bin
f0bf0cc433ebefd339880f246a5877f95a5f0c4334767de73316d92caafdea73
pdf-font-stream PDF embedded font (sfnt) at offset 0xB230 14644 bytes
font_01_sfnt_off0000d6b3.bin
e9bb4a117b6bc4c892273f361fe82e81ecfef5ccd6abb2a9832ee781264c8648
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6B3 11080 bytes
font_02_sfnt_off0000f063.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF063 16792 bytes