Malicious PDF — malware analysis report

Static analysis result for SHA-256 234b5a6f04597633…

MALICIOUS

PDF

90.3 KB Created: 2021-09-04 07:13:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3cbed5551599b7f7e1d7bd40dacbfe35 SHA-1: 61e6f8ec6c68bcbbbcf7a6be1201f8c3da6d5c74 SHA-256: 234b5a6f04597633588a0b23a2b4f42eb2380ec4efc8b18ecc6bc0ab52395ae9
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings suggest a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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 https://chcial.ru/uplcv?utm_term=towers+falling+full+book+pdf PDF link annotation
    • http://indianspringhomes.com/userfiles/files/supumalidalutagomitotozu.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606de7c07b770---65233707182.pdfIn PDF document text
    • http://generale-bureautique.fr/gdb/files/file/21733139500.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f13a61030a2---sazupakupiw.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/pirapeno.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ce18a1b78f7---87989489994.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/92358285688.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/56231291969.pdfIn PDF document text
    • https://anyimaker.com/upload/users/files/taredezulovug.pdfIn PDF document text
    • https://kudamatsu.org/userfiles/file/turekar.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160741e4060d2b---77771179552.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/0bb25cac618d0c819ad10fd6b8f9355c/25609073656.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/82334906112.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/zawemibup.pdfIn PDF document text
    • http://eclickapps.in/userfiles/files/guvixusep.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/wovajuwoz.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/41588319690.pdfIn PDF document text
    • https://loctra.net/userfiles/file/48142080522.pdfIn PDF document text
    • http://tunesistudio.eu/userfiles/files/gisaluwozejodipumivik.pdfIn PDF document text
    • http://bdn10.cz/files/file/jotirulogajur.pdfIn PDF document text
    • http://biotop-zamosc.pl/userfiles/file/84728844755.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/75274999947.pdfIn PDF document text
    • https://mojer.bg/files/nusenute.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000f5f3.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF5F3 18592 bytes
SHA-256: c32c792ee2bfe14cd290d3d1768ee646c810f3e6e9a328503813bb5ff75e16d0
font_00_sfnt_off0000dcd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD1 10956 bytes
SHA-256: 2a96cfe058696a96e84c14325e3f92086906afad51197a2909e9558a4e7cd3b1
font_02_sfnt_off00011362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11362 18588 bytes
SHA-256: fa2f26beea865406ec66319490c299ee90982f559109b1a69e244f1c76eade21
font_03_sfnt_off00014332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14332 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1