Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd351b10500b8ef2…

MALICIOUS

PDF

99.7 KB Created: 2021-07-03 08:38:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b1b456099715e5900219b96d0b1bc875 SHA-1: 32f4e5db2f628c60d289390bc4f68a43525b2c33 SHA-256: fd351b10500b8ef2f36852e427138ac4b7c025d912eeb08b95feee46b44d9912
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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 https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2846d9b11---wigibukujuvemajulodo.pdf In PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b80638296be---vanunamiti.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/924f29a8d532791968a3152cc8b6c608/99009292019.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/8v7qf13eglf3trec9k7ut4hmpp/wakobelexidubarebulonewos.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095962d6af43---40385628167.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/ca7dba7e1643df1c15648bd6eee290f8/1552063940.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-6-28/20210628132450627952.pdfIn PDF document text
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080facb23ed1---mapudomo.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/15028060725.pdfIn PDF document text
    • http://diclenakliyat.com/userfiles/file/xemugojov.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/16097453727.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/wiberipalalevitedaxak.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609ccae0c3c5d---74684912153.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/49029047331.pdfIn PDF document text
    • http://korvet-sp.ru/userfiles/file/94211123820.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/1de114b0734f7f76cd7b51e1d5c11b09/12699048743.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe34ddcb44---mazim.pdfIn PDF document text
    • http://bahattinburyan.com/userfiles/file/nuwavegurado.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/49236878030.pdfIn PDF document text
    • https://smilaxlabs.com/userfiles/files/vuropobegabiw.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/rusebilivemugunonu.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/c1a3ca67f9c8b1ec8212999a0ea0f88d/fatitu.pdfIn PDF document text
    • http://riggi.ru/userfiles/file/dorekonaz.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ba8e19267bf---16208328047.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/k81jacrssnkqq7h1tvptam6iln/48050909541.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=cheesy+home+quotesPDF 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_off0001235a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1235A 18120 bytes
SHA-256: 60039381aafff9a926003ea0a210e77efac69896cc0784262aa8bed6daa5cf1d
font_01_sfnt_off000152af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x152AF 10260 bytes
SHA-256: 9123086b6632c592aa8d8121f7a3ca7024092566b7cfa7256deb6dc247194c31
font_02_sfnt_off000169de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x169DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1