Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5bbea24c9cc5791…

MALICIOUS

PDF

74.4 KB Created: 2021-05-24 16:30:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 4b75e95fc95565ac926a942295d01fd1 SHA-1: f2c78de85894e452fe46a5c0123ee5956b2060a1 SHA-256: b5bbea24c9cc57914e681e44bdd304d2411148f22a6c1ecb8b237fb3bae77dbf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. 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 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://chcial.ru/uplcv?utm_term=impersonal+passive+exercises+pdf+with+answers PDF link annotation
    • http://netinflux.net/userfiles/file/bademulekiv.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b6f2f789180e0ff3dade8b466e6392eb/92328353455.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083eb7b30634---78633893150.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/rezabivegadifedepanorivas.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/74f25f0738bec1acefa08866206b58e1/77659173442.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911caa41f95---95114150146.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/31270283041.pdfIn PDF document text
    • https://binarbaidrealestate.com/public_html/userfiles/file/xejek.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2a510a95c---65132474167.pdfIn PDF document text
    • https://otelnamore.com/wp-content/plugins/super-forms/uploads/php/files/110b7c01281677a2c46183ff0cec4b4f/bogomadutajevivowo.pdfIn PDF document text
    • https://askopenko.com/wp-content/plugins/super-forms/uploads/php/files/dc7744f0d34cb0fa604afdc08babf522/wegebiramejoluzob.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/649e68d2047bc9d25c3c75b5ea3dc08f/65838908160.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872fc9986dc---vuzadetuxelijemidof.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fa8d405d6---62957585301.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5139a4e405---nozolopav.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/rnf4b2949i6ufb8n2poto763dp/8584178323.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1gflp7sh9pqe4gd92n11lhblk4/11013625158.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7eda975f21---7275961643.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb7b273c0f---29563694963.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_off0000d80e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD80E 5552 bytes
SHA-256: ebbb77e1291e42a85c04a402d405bd1483633d187d9a00301e94848424a6abbe
font_01_sfnt_off0000ead0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD0 1800 bytes
SHA-256: e9a5a1f6ed95b1e3669933bb00002ad32a1708c3e0b735191cad5e02368a6c7d
font_02_sfnt_off0000f35e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF35E 11244 bytes
SHA-256: 5dfaf462b2d92856152f1dd82b91279109130e3b060856bd126b68a9dbcd4124