Malicious PDF — malware analysis report

Static analysis result for SHA-256 b51862723a85404f…

MALICIOUS

PDF

84.9 KB Created: 2021-06-29 03:34:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d9d26f61fcc17eee24d9cf3e0571abc5 SHA-1: a18ef475d33c54db930dbcbed43226385866e585 SHA-256: b51862723a85404feb326b1252c0378e5e64eb971d63cce089af7acba06e72a1
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple websites, many of which appear to be hosted on compromised WordPress installations. The ML classifier strongly indicated maliciousness, and the presence of numerous links on disposable hosting further supports a malicious intent, likely for phishing or distributing further malware. No scripts were extracted, limiting the analysis to the URL-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • 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://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af66e63da9e---46072900043.pdf
    • http://woori-tour.kr/FileData/ckfinder/files/20210614_1780B75A9A8FC2EC.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/e9512949c5b54d1aa151f9068ae475a0/dufeliwu.pdf
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b48a63cad04---33866925740.pdf
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/7fe3b11b40a12a8fbd2f5baf0d778fc4/migefofejibitu.pdf
    • https://eurouniversal.eu/ckfinder/userfiles/files/69313639433.pdf
    • http://thementalhealthadvocates.org/files/userfiles/file/jedaro.pdf
    • http://pokewaveanaheim.com/uploads/files/43520760618.pdf
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a119c9198---10253587141.pdf
    • http://dwhs79.com/clients/15834/File/gabafur.pdf
    • http://smolensk-bakaleya.ru/userfiles/file/5013119387.pdf
    • http://cuatro-pr.org/sites/default/files/file/64709206280.pdf
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/j3seql63mp165q4okp79oi65ok/fukufulitoris.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce2c6d7c20f---94388899442.pdf
    • http://ajisushionline.com/uploads/files/61666835919.pdf
    • https://asoriofrio.org/ckfinder/userfiles/files/gisuweveje.pdf
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/selaxogawetubakukikiru.pdf
    • https://anfauglir.com/images/file/paputi.pdf
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160ab60b9b39a1---wijuruworudosukiwuvil.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc53b09897---famololigoli.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/2fivnisk3ne0oas8vnlchcm0e6/23977562670.pdf
    • http://blpest.com/UserFiles/file/fuguguwe.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=effects+of+employee+motivation+on+organizational+performance
    • 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_off0000ea11.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA11 16792 bytes
font_01_sfnt_off00010228.bin
e2135a9e0a3e181977d5d8106c211ea1553a379ace26aa1015acc2c93284db52
pdf-font-stream PDF embedded font (sfnt) at offset 0x10228 11048 bytes
font_02_sfnt_off00011bf2.bin
dd6a74a673c970c165bf9ab15927c84881369c5d20060821d8929c7e88e3b483
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF2 16232 bytes