Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef1e678051f5b39b…

MALICIOUS

PDF

78.8 KB Created: 2021-09-10 13:45:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 00b066c871552aba5c43b9fba541754f SHA-1: 905d846dbb3cc19b4ca9133f8db73a1a157d12b1 SHA-256: ef1e678051f5b39b6a8078828f48a7ab819a8c990a324896e8c5b2b0ab3612e8
174 Risk Score

Malware Insights

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

The sample is a PDF document that contains embedded JavaScript and multiple external URLs, flagged by ML classifiers and ClamAV as malicious. The heuristic 'SE_BROWSER_INSTALL_LURE' indicates the document's content likely prompts the user to install a browser extension or update. The embedded JavaScript and external links are likely used to download and execute a second-stage payload or redirect the user to a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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.
  • 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://samirkumarpaul.com/ckfinder/userfiles/files/66940876333.pdf In PDF document text
    • http://gabident.pl/local/userfiles/file/42542243037.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/9241684719.pdfIn PDF document text
    • https://maffart-guy.com/userfiles/file/49840664451.pdfIn PDF document text
    • http://bawaconstructions.com/editorData/file/56033347434.pdfIn PDF document text
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/tasalitevotasifef.pdfIn PDF document text
    • http://peter-crooks.com/userfiles/file/wolebitoribozesobepel.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/vopalirek.pdfIn PDF document text
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210909022826042022zl0p0g.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3ec59b554---72651649747.pdfIn PDF document text
    • https://eletroluz-al.com/_IMG/img_internas/file/guvidikax.pdfIn PDF document text
    • http://jubileejec.com/userfiles/files/tikopanaxisug.pdfIn PDF document text
    • http://sampoernastrategic.com/uploads/image/files/83856777018.pdfIn PDF document text
    • http://rassadaspb.com/new/files/file/luwafoligadeku.pdfIn PDF document text
    • http://assisdrive.pt/userfiles/file/13358797100.pdfIn PDF document text
    • http://www.electricman.in/demo/frontend/web/uploads/files/14770144393.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210907_034744.pdfIn PDF document text
    • http://yanartextil.com/firma/files/sibenereviroxe.pdfIn PDF document text
    • http://aasghsflqsae.handylover.com/upload/files/godejinesosilugafopav.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/50634140328.pdfIn PDF document text
    • http://syarmarka.ru/userfiles/files/bagaf.pdfIn PDF document text
    • http://printific.com/images/contentimages/files/90504516179.pdfIn PDF document text
    • http://tulga.ru/editor/files/71524702584.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=homepage+firefox+androidPDF 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_off0000ce32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e644.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE644 18236 bytes
SHA-256: 0d5b6dbcabb04fb1ca15f08b29638db66c3e5b00f30cd4cd6637371c0afe1f2d
font_02_sfnt_off000115c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115C1 10620 bytes
SHA-256: 7d9fb2a981c37236a0d1f6462ded1afa8aa84fdf42e7b871d1ba79ce7a886896