Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4b844f6b811cd7c…

MALICIOUS

PDF

79.8 KB Created: 2021-06-25 13:35:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0d06fba17a4497ed275d66bfa1199e79 SHA-1: 4edac125e0ce67687efa98b3b6ad98941c8babd8 SHA-256: b4b844f6b811cd7c6cbb4a91efcb2d7b44e8535ec95a2d00e21d8cff6fb3f239
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites, designed to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure suggests a lure for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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
  • 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.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16078bd07e983d---teriridupalekene.pdf
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16081ac7307026---robutusololen.pdf
    • https://wagaskar.com/media/gejufadaxinasowababor.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a246828d315---40304174729.pdf
    • http://poltinik.ru/userfiles/file/98833776902.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/k78evi8t5def2uqf3blqt433vh/mokuv.pdf
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a297c577fde---74193936991.pdf
    • https://pfhotel.gr/ckfinder/userfiles/files/xarogoxojabegunazenoke.pdf
    • http://pune-india.info/userfiles/file/zuzutawokitonowa.pdf
    • http://www.cenlafilm.com/siteuploads/editorimg/file/rigukono.pdf
    • http://korean-school.hu/hangul/userfiles/file/21430343914.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9c5adf058---gisowatub.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=lippincott+manual+of+nursing+practice+8th+edition+free+download
    • 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_off0000d1f4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F4 16792 bytes
font_01_sfnt_off0000ea06.bin
3724f73fff447ba6e63b98851086050980652a98a4a76a3c5599ccdabeef59b7		 pdf-font-stream PDF embedded font (sfnt) at offset 0xEA06 16888 bytes
font_02_sfnt_off000115c3.bin
a5b783ed6f6fb3b8a447b3c445279f5118e9e74e9880c9d40e9c65972c893e84		 pdf-font-stream PDF embedded font (sfnt) at offset 0x115C3 11420 bytes

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