Malicious PDF — malware analysis report

Static analysis result for SHA-256 b09cb0895a4a7b49…

MALICIOUS

PDF

80.4 KB Created: 2021-10-09 12:58:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b148598527feff29933d8a8916ad7c05 SHA-1: 8a9efca7ee43bcbfe566ed8749a034cc12c96649 SHA-256: b09cb0895a4a7b49774499334d79213646a983a2f7442536c45b6c0b6771a157
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating a link farm hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to phishing or malware-hosting sites. No scripts were extracted, and the document body was unreadable, but the link farm nature is clear.

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 https://marsanz.pl/uploads/fck/file/pozalozilagexiketolano.pdf In PDF document text
    • https://limblength-sldf.com/userfiles/file/sumuzojujanaxetun.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1614d5d69c703f---79554819260.pdfIn PDF document text
    • https://lee-trading.tw/archive/upload/files/10262220823.pdfIn PDF document text
    • http://hoangminhphatkorea.com/webroot/img/files/27204039813.pdfIn PDF document text
    • http://helenhotel.vn/upload/files/bodarusizofeki.pdfIn PDF document text
    • http://identik.hu/editor_up/moxarekelige.pdfIn PDF document text
    • https://mobisteelegypt.net/userfiles/file/98447886816.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/dabepagidagejokog.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613df0d8000dd---54450842859.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/14535885593.pdfIn PDF document text
    • http://viorina-deko.com/images/file/32892083737.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents/files/zedabefezulixag.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0becb8dd4---42074974774.pdfIn PDF document text
    • http://budka39.ru/files/vebogubufaxupunes.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/libexutovifobed.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/40174018730.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/jusefaritifovovixugati.pdfIn PDF document text
    • https://qnzar.com/files/woditodulusozamikogunase.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/files/norapevat.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/jipenepekigefixisoforaza.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/14939125421.pdfIn PDF document text
    • http://yugang360.com/upload_fck/file/2021-9-21/20210921211529571942.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/sibirizirogazixalav.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/volifimitolunujulonuzuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=0+by+4PDF 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_off0000c8c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C7 23552 bytes
SHA-256: 3baef97f23acd3b94ed1d19f61e8d381cdfddbf867af692de41a5a04d7205e1d
font_01_sfnt_off0001069e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1069E 9436 bytes
SHA-256: b4d17c9869694d3a9062e69bbe4f26d2886e0da3037c49b6afc6ed689e3fc233
font_02_sfnt_off00011ad5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AD5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1