Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f3ded0327e52508…

MALICIOUS

PDF

85.0 KB Created: 2021-06-25 13:13:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 7b5f200cacd6cc5e8a4126fc40641ac2 SHA-1: f869cd52c9ece6b7705a65ef35c2ee27b9357faa SHA-256: 8f3ded0327e525082073a9a125d98b3ff44dae9cd7a397b1767bf2d2d97fa8b8
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and a link farm pointing to compromised WordPress sites, suggesting an attempt to trick users into downloading a malicious payload. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded JavaScript indicates the potential for further malicious actions, such as downloading and executing additional malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 8

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/aqh5f0ueg80t1se72ql3l4knd6/77819097467.pdf In PDF document text
    • http://mosjob.ru/images/file/sumaluzi.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021052506384647.pdfIn PDF document text
    • http://scales-center.com/shop/fck_file/file/dimev.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ca264be65---70210038271.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba01805ab8b---32942986285.pdfIn PDF document text
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/c988e7e90632961afd94d00a0fc09c0b/4314224314.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/gtm595lahm58sm604052lpfmfr/wawufitupulefusun.pdfIn PDF document text
    • http://nelly-design.ru/upload/files/10619021833.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/36f522ee0a306757f1654aafe5dc7feb/tarozivumakinifimijim.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/cfcf70b7a01a8c0a67997e96e16654b4/65523583155.pdfIn PDF document text
    • https://www.ideaklinikbursa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ecebaccdaf---sofopinigefog.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16073cf949e57a---4666921953.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=how+to+remove+horizontal+line+in+wordPDF 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_off0000e839.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE839 18204 bytes
SHA-256: 365b82dc1141587a5f167dac35149dd5a2acecbd4a4c85b72447e0b460eaab1f
font_01_sfnt_off00011769.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11769 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F80 10548 bytes
SHA-256: 6b6f1934b52a48ebd65fa52e6b646fd085d168383bdda06411d789d75c2b2833