Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcb420f6bf09d8f8…

MALICIOUS

PDF

79.1 KB Created: 2021-09-13 09:20:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: af1c4733ebd1a1b004b7ed9a8e46e21e SHA-1: b3f55e1344cb7118e2c7238262f4a86101b57dab SHA-256: bcb420f6bf09d8f897f7bbae243cdf09363a2ffcf0299a1919e2cf7158f74cdf
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which point to disposable domains, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to redirect the user to these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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
  • 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://huiking.cn/uploads/file/091334362947.pdf In PDF document text
    • https://www.benkorner.nl/admin/library/ckfinder/userfiles/files/86667912451.pdfIn PDF document text
    • https://reparation-mobile.net/userfiles/file/98477925895.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613785883811d---detenetepetolumukikimep.pdfIn PDF document text
    • http://a-daily.jp/app/webroot/contents_img/files/20002384475.pdfIn PDF document text
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/41246262282.pdfIn PDF document text
    • http://mindentudor.hu/userfiles/file/gagetatukup.pdfIn PDF document text
    • http://www.centralperdana.com/file/3117538077.pdfIn PDF document text
    • http://www.jasolasia.com/image/upload/File/pigosolid.pdfIn PDF document text
    • http://gesundezellen.com/neu/userfiles/file/titaxixazofonujamum.pdfIn PDF document text
    • https://hotelcorona.ro/files/lukejujulabuvanebozekem.pdfIn PDF document text
    • https://grupo.iberia.es/js/ckfinder/userfiles/files/lefapisifetamonufojiwit.pdfIn PDF document text
    • http://lj-group.cn/upload/files/zivimetulejumafaxap.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/42286571204.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/57427897941.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/7sol010tl4a679tmt68cgbbjgn/xerekuwaduzabawul.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/18323655787.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/sitazi.pdfIn PDF document text
    • http://coolscape.info/images/files/jisule.pdfIn PDF document text
    • https://sssmri.com/ckfinder/userfiles/files/56369977676.pdfIn PDF document text
    • https://suruburi.net/mm/file/29581775405.pdfIn PDF document text
    • https://auditorescr.com/ckfinder/userfiles/files/42192083758.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/zubosatujisubunepijisipo.pdfIn PDF document text
    • http://szentimresiklos.hu/upload/file/deduwotiwilekob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=gears+of+war+ultimate+edition+trainerPDF 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_off0000cdcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDCF 18304 bytes
SHA-256: 71788a5414d9f04c815f3d2443db3daad608a3567d5f36f6935d2aec5956f601
font_01_sfnt_off0000fdc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115DB 10740 bytes
SHA-256: 3861579766e534e9130026280a1194bfd72d6b21bf5c1b2f6fc66b0e15e9afdf