Malicious PDF — malware analysis report

Static analysis result for SHA-256 799121aa70d35799…

MALICIOUS

PDF

68.1 KB Created: 2021-05-10 21:58:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 6ab8eecd761236e149dcfc30b20b782d SHA-1: 1ba78919b677e670b369ae4bae38605bf61805ea SHA-256: 799121aa70d35799c29330210f2fce2721531c0779ae6c3aa81274e232d3e461
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document employs social engineering tactics, impersonating a cloud file-sharing service to trick users into installing a browser extension or update. The embedded URLs and link farm structure suggest an attempt to redirect users to malicious sites for credential harvesting or further payload delivery. ClamAV detection and ML classification confirm its malicious nature, likely as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Cloud document impersonation lure medium SE_CLOUD_DOC_LURE
    Document impersonates a cloud file-sharing service such as SharePoint, OneDrive, Google Drive, Dropbox, Box, or Microsoft 365 and asks the user to open, verify, or access a shared document
  • 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://krisoc.ru/uplcv?utm_term=chrome+app+launcher+free++for+pc
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/09d3e3aa2d1723ce5e642dc1a62af961/duxizobosimela.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d58e8a9712---71371265201.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/158119d4212607073e32ce6561c11772/kodew.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607b32654a7bb---kedebivesupo.pdf
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/54fa5746d4870ac73e80b517fbd154a4/ririworuguzuresedew.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1608caf537e2be---31880019303.pdf
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/750dce1eb55b06440be2509f1ad86ad1/parez.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160717b417e098---revaliwofevazogivuk.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbedfcfbb8---69020923943.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160831893a8560---7629956721.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/16085940794a58---maluv.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/e032dbfdab88fc75297dae4823711da7/sazebo.pdf
    • http://albatrossmrn.com/konadnew/userfiles/file/pabenusarisegonipisi.pdf
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb79c6df2d---45034634004.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16084da4e5466e---vibajopevajovo.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d160.bin
3d94cb0f28aad471ddf0e95ad2fdf864ae13de79f01baf42986d3c7d5de60300
pdf-font-stream PDF embedded font (sfnt) at offset 0xD160 4980 bytes
font_01_sfnt_off0000e223.bin
1b13e1e890884d1a388b40b796fad64e73a08fca26c339ab992cd6d5e42e7d46
pdf-font-stream PDF embedded font (sfnt) at offset 0xE223 9840 bytes