Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8f2e900eac567ae…

MALICIOUS

PDF

95.4 KB Created: 2021-06-28 03:37:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bf88cc377b93a792dfa8c33d36c5478f SHA-1: 616805694bb0676c4a753cc94c423190b9bd2bf9 SHA-256: a8f2e900eac567aec06f07ae4e3ac2c14389bd3ba900e007d5d324abcaea88ee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress upload directories and other disposable hosting. The primary purpose appears to be directing users to malicious content, likely for phishing or malware distribution, consistent with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://krisoc.ru/uplcv?utm_term=yellow+fever+is+caused+by+which+mosquito
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/88eddtai1rv313tev352t5o1eq/37818926273.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7fc247b7d8---34613473053.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093dc9049e81---muxiroguri.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/dfa37319a90dfcb64525c2249e7c31a1/dawosujawesinu.pdf
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/a86bd613bdcf77d41fb83cc57c21c1fa/39404165414.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16084a76c17698---9712390441.pdf
    • http://clinicaveterinariasangiacomo.it/userfiles/files/24435937375.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160909e3338b20---49037285830.pdf
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/tt7dl8vu062ftod5e6240j2p34/gefed.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160742a2378958---lukopagowolorivukapuvi.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb9f0ce0b8---98377655490.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16071e4c23f711---43680149896.pdf
    • http://aisef.org/uploads/userfiles/file/file/41516560932.pdf
    • https://hr-serdahel.hu/images/file/lotovaduzop.pdf
    • http://cnkls.com/userfiles/file/1623666302.pdf
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/473c05622e3f303683ee19a6cb402f60/fupegajakutifosizapebo.pdf
    • http://amadpich.com/userfiles/file/15882565000.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7270039ad---degosufupuzafisowotora.pdf
    • http://urparitet.ru/admin/ckfinder/userfiles/files/jajidu.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084f9763b612---zexoni.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb76c2afff1---43698069474.pdf
    • http://littlepearlspublishing.in/data/eimages/file/gufedosa.pdf
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16071822eca1af---9378476136.pdf
    • http://1960vonsteuben.com/clients/d/df/dfb5e1b83ea85bfdc5ef1da934264264/File/26919581307.pdf
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16092960cd40b1---nisir.pdf
    • 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_off00011056.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11056 16792 bytes
font_01_sfnt_off00012868.bin
0137f93ffa4578e6fddfe236cccd80f39fde5b90ba7556031cef0169c2ab8611
pdf-font-stream PDF embedded font (sfnt) at offset 0x12868 17360 bytes
font_02_sfnt_off000155da.bin
da9804655779f0c68ba2d67273abb808656dcb110e3a3396584191d3ee3418ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x155DA 11272 bytes