Malicious PDF — malware analysis report

Static analysis result for SHA-256 40e36166cd8e20a7…

MALICIOUS

PDF

74.6 KB Created: 2021-09-21 05:59:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 36c805725ade3d320501e5933407ee8e SHA-1: e74aaac5c64bade971e7ff89eb880def3ff559c1 SHA-256: 40e36166cd8e20a7e0eb412b3f71991ca688337444c14042847c32bc03775f9a
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories and disposable hosting, likely to redirect users to malicious sites. The presence of these links and the nature of the hosting suggest an attempt to lure users into downloading further malware or providing sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://study-go.info/wp-content/plugins/super-forms/uploads/php/files/4943b56900aedd7f2f0fef38ba8f4d3d/19340406969.pdf In PDF document text
    • http://olynskiconstruction.com/pics/file/42296322047.pdfIn PDF document text
    • https://otterdisplay.com/userfiles/file/samudores.pdfIn PDF document text
    • http://playitdirect.ca/ckfinder/uploadfiles/files/83829993649.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/20d08a40e45b050a2c2adb75b5a9aad0/74500228251.pdfIn PDF document text
    • http://eichler-kammerer.de/82441012653.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145ab28870dd---zesebotuxe.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/1000616495.pdfIn PDF document text
    • https://sesconbs.org.br/ckfinder/userfiles/files/21705610573.pdfIn PDF document text
    • https://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/suluwub.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/37553520001.pdfIn PDF document text
    • http://bolshunoff.ru/images/wysiwyg/file/pamepapuzov.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/161375397b908c---80686728463.pdfIn PDF document text
    • https://qigoodteam.com/uploads/files/202109010106463929.pdfIn PDF document text
    • https://kaskad-74.ru/images/uploads/99562002086.pdfIn PDF document text
    • http://asiancfea.org/userfiles/file/sokasixofawumere.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/mumena.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/16415465047.pdfIn PDF document text
    • http://pnc21.com/files/fckeditor/file/1718005139613a85c07566a.pdfIn PDF document text
    • https://lidiyageorgieva.com/ckfinder/userfiles/files/99966247256.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/65b836541a99b33b4d34ed085afa93b1/66764496812.pdfIn PDF document text
    • https://laser123.com/geektic/files/rosat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=mp3+i+wanna+grow+old+with+youPDF 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_off0000bea3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEA3 10836 bytes
SHA-256: 6045eb7897a209cca56cabb7b0dbf5cd8f65231e2d62eabe6b32e7f77cd2dddd
font_01_sfnt_off0000d768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD768 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7A 17692 bytes
SHA-256: 28ec658a81e185e8b19f5771c14dc0a68f643aa84a72c1f273563953f8c46e85