Malicious PDF — malware analysis report

Static analysis result for SHA-256 d857b2e338e71fe1…

MALICIOUS

PDF

89.8 KB Created: 2021-06-29 21:09:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6151117b04cefaaed3410b9b6976642f SHA-1: 1e85f96bd6633d6d1a5f6c8a3ed85f575457890a SHA-256: d857b2e338e71fe1ac8e61d67e2ddd0e37736ee9c046cfb24eeede362530e1cf
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised CMS uploads or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded URLs suggest a link farm designed to obscure the final destination and evade basic detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://ekransamara.ru/files/65693245574.pdf
    • http://jrpst.pl/userfiles/file/94584076773.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd5d387a4a---2455053951.pdf
    • http://adveotec.com/img/file/20563622541.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/bbe6ff0a1670d9c5fe94a98e150b762b/72937383816.pdf
    • http://planbmedia.hu/files/zikowa.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16086023a50409---86836453515.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076d993601a9---mezasawewedeg.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/656fm4v684cbmiglcp9enf1m92/85642338315.pdf
    • http://www.allatpatikapecs.hu/images/file/vixufigiwebonakowebekedax.pdf
    • http://anhuifan.com/upload_fck/file/2021-5-22/20210522020909571242.pdf
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/7jmdv67e8c4r3d56q386vvj51s/24701406722.pdf
    • https://robert-zauer.cz/userfiles/file/32142007964.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/90a79d00250890eb02d8bc827046e995/19693821231.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077b91ea9d38---18286845949.pdf
    • http://www.elitagida.com.tr/wp-content/plugins/super-forms/uploads/php/files/t30siici5ens7aclodd37h8cr4/jisok.pdf
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/ad50f9101440858958fc9ee02ddf6680/90066889510.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f155c378d---leruxigilifubaga.pdf
    • https://soudurelauziere.com/upload/editor/file/buwumemanivovoneko.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/23c25e7ht5a4djn7ah7emoimmp/gerepejuzaririwerufadelo.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160728e662566c---lodijazitegovezekupikek.pdf
    • https://electroagro.es/pub/files/pazegevaja.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=mmorpg+android+not+pay+to+win
    • 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_off0000fde9.bin
de94ce3734f297db5d968f4d56d03001fcbbe3aafe05dfd6a6af0129d9f94952
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE9 10580 bytes
font_01_sfnt_off000115d1.bin
534485c981f6675e2fa1662e0e8645648678961e3ff900329fa917cc366e9b19
pdf-font-stream PDF embedded font (sfnt) at offset 0x115D1 16880 bytes
font_02_sfnt_off000141e2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x141E2 16792 bytes