Malicious PDF — malware analysis report

Static analysis result for SHA-256 13c37d23379fa744…

MALICIOUS

PDF

79.4 KB Created: 2021-09-03 20:15:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: dcd0d40fb920c14606400026250ef8f9 SHA-1: 9babd2536f25b92ed5d371bac6334d98a2a2f81e SHA-256: 13c37d23379fa744afbb4f7dc20a94fb99eb087d94c0696445c8d771cb51af1e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or other potentially disposable hosting. The ML classifier and link farm heuristics strongly indicate malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9781

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://sosonomo.com/ckfinder/userfiles/files/89622732346.pdf In PDF document text
    • https://yenhuy.vn/upload/files/dasasajepo.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/39321695889.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/jimogifetovusoz.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfcdaa9ffd8---woxuvaza.pdfIn PDF document text
    • https://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/rl2kd3t9c2qe7vh9td48o7dto1/datanofiberepanunej.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/70707591990.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fed4a32b0c---81159231852.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/mcp5lrfojq6q0t0m2c9v1h1h40/34317387072.pdfIn PDF document text
    • http://neoneofitou.com/ckfinder/userfiles/files/65664068811.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/8834ebb303aada64a445e4599490d41d/5903964320.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/bf051683018752dfe0b71cd5b3c8b01d/69960043130.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/nifefavaj.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/psb3pmpuh1sna3fqf14c7918p7/51134960702.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607021b26b9c1---90649737670.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/1ptbfh2qod76u7n9vfo0d22uq0/83631315589.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/a5a892c6cac98022641abdcbea9f8172/lagipidimosoti.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/tiwunatogev.pdfIn PDF document text
    • http://yachtandgulet.com/userfiles/file/77795772894.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611aba7b533ad---doxubutanubulipuxukenufa.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/50136587608.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/19705008000.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ce9f80f0b6---54607177078.pdfIn PDF document text
    • http://chieusangducphat.com/uploads/userfiles/file/xebisupokobo.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/6451768861.pdfIn PDF document text
    • https://airbays.com/userfiles/file/29713446219.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=sach+trang+quoc+phong+viet+nam+2019+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b629.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB629 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE3B 18164 bytes
SHA-256: 2f560cd62b8a95ce79a39ad14191a6486f9db044f61c605a99ace3d2252e6e23
font_02_sfnt_off0000fc94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC94 16152 bytes
SHA-256: 0f62411f33c11177563efe33ebd0105f37df2a55e6a92cd5aec3f2cc21bf3838
font_03_sfnt_off00011228.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11228 11704 bytes
SHA-256: b92e939c1c0fb27012dc2a0b6bf5c34f332714dd761b1dd6a71155b4e5c4162d

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