Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f33a80e9daeaeae…

MALICIOUS

PDF

75.5 KB Created: 2021-06-10 06:15:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 0d95c09d36a2119b216a938c6b474902 SHA-1: 0754581088a5f231e3ff0bc0a58ee87954cd7b17 SHA-256: 7f33a80e9daeaeaebd18b6e119bc64b91eceef1a37267c3f5a709fa60f3a95a6
196 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake browser/software-install lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://laborke.ru/uplcv?utm_term=online+pdf+compressor+to+50kb PDF link annotation
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1609c26ef46c91---83781879723.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16098a52f8214b---61298155462.pdfIn PDF document text
    • https://cuacuonbentre.com/upload/files/pinaxodibesubukulivesoru.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d001d1716c---40345026891.pdfIn PDF document text
    • http://easyreturn.store/userfiles/file/11246189180.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/ba1e76d2147f16a242ebdec41d6a3e2b/fegogubom.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/89247749881.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1609a791a5fde5---52455928035.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa1307e49a---kebuvosizawuj.pdfIn PDF document text
    • http://childhood-matters.com/clients/49507/File/69285625816.pdfIn PDF document text
    • http://asbazainville.org/userfiles/file/42209580805.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609821b6729c9---72677367781.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2501be1a631327c3ac9068c3bf25a690/59788389228.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1bf7d8e6f---4674854355.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE05C 5588 bytes
SHA-256: 2eb534db2c52d8039b672147890e5257be1275e46b8fd0f65f74c32a867d0b54
font_01_sfnt_off0000f344.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF344 1800 bytes
SHA-256: a36eee06fef6ce219692c4ec918276ac99413e4fd1e3666e4031624f9289d620
font_02_sfnt_off0000fbd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBD1 10356 bytes
SHA-256: de40c4d314faaee2de4603e1c3d73eccbcec5c47dae317594c184c857805fafb