Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8f5156bf828f84b…

MALICIOUS

PDF

88.9 KB Created: 2021-08-01 12:20:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b2cb2fdcb92ae084d34575f1906a123b SHA-1: d9c9f0530fa6ea93ee3e5f93cbd0486b29706d3d SHA-256: c8f5156bf828f84b53e4695d3882adcbc5e1aa0e6bd53819745ef61565627f26
96 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many of which point to compromised WordPress sites. This suggests the document is designed as a link farm to distribute malicious content or facilitate phishing attacks. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://promocode.lu/userfiles/files/11347566860.pdf In PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16089137672f53---47457097391.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/62282161537.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607add1a37295---91301259096.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/7igcm1usi8c0h3j3890hofid1r/rozezegijujewopon.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/6f515e98477a9f6e21de2cd927295907/34509798241.pdfIn PDF document text
    • http://nyett.hk/uploads/news/files/kufadotazewagirujupumegek.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/38983500414.pdfIn PDF document text
    • http://firanywiktoria.pl/uploads/editor/file/kanadof.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/matuzozirotaladivuxi.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607e04522f7d0---56464417038.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608df66b01a14---51052971157.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c3f85c157---jomopoludedotovopusovel.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/gituxofi.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/nozubuvusalikojoziwile.pdfIn PDF document text
    • http://fecirturizm.com/resimler/files/xaxixawesemidupu.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc6d81981d---bexituteb.pdfIn PDF document text
    • http://euro-ex.com/images/blog//file/17026678942.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/detasejoxexupasul.pdfIn PDF document text
    • https://rubenferro.com/userfiles/file/gulolorikem.pdfIn PDF document text
    • https://www.propertyadvisersaustralia.com/wp-content/plugins/super-forms/uploads/php/files/c669694332484224c1b9a37720391077/wenowimovejinuduriw.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c0f0a75370---37838277662.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160852d4a0847e---31117339341.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/7619cf22a3998b4d0cc809d63426cdec/8072503105.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/xavoxafopadamobo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=expulsados+francisco+jimenez+comprehension+questionsPDF 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_off0000f2fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B15 11404 bytes
SHA-256: 9d93f93d1cb238241d3f0bcd031bfec4e1a6d7c4d3086cacf8fce885ecd96b0d
font_02_sfnt_off00012599.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12599 17696 bytes
SHA-256: d2f4426fab738d4e6528806006590a00890054edc879a1440b15e49756ee5377