Malicious PDF — malware analysis report

Static analysis result for SHA-256 138d9ee504c8935b…

MALICIOUS

PDF

73.6 KB Created: 2021-06-24 22:18:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 994214253e1f80cdc0dbeed785a6d6b0 SHA-1: 16e4f3d644bf5cf49eedb9fe6481bc4cddd87cb9 SHA-256: 138d9ee504c8935b77d536173690866f835f927e1099afc89f31c7f62be9841f
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 0.9847

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://acronimocostanzo.com/userfiles/file/67761363892.pdf In PDF document text
    • https://artenika.pl/fck/file/24089110797.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608078d1a2b5c---17151700715.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/b4285ab535cb665aa9f076ea6d327a13/lonukab.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad048b7412a---jekepufefuwigube.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071caeb8f2cb---69937257616.pdfIn PDF document text
    • https://elearning-chemistry.ro/userfiles/file/15835257070.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b3cd08b7a---42590023543.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/95290434234.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160724750a1d8c---17959968629.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/gifekuruwasadanakuxomimur.pdfIn PDF document text
    • http://hydrem.ru/images/file/62913865313.pdfIn PDF document text
    • http://ssteelelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/40888056615.pdfIn PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/h8qjtq0vtapond56roaumfo906/30432524287.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd696d467c---41186467118.pdfIn PDF document text
    • https://kodcomputers.ro/2664/uploads/6150672750.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/3f826bf7ea3cba35a7e411d3f33c8d0b/defoxazipesig.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/qg1uk9c7l32pgjqbq81nc6btgt/denimunolarukowevivogeten.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=exprime+tus+neuronas+pdfPDF link annotation
    • http://scripts.sil.org/OFLIn 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_off0000d30b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD30B 5180 bytes
SHA-256: aba0a269d84db24da382afeeac66b626c0446de6560a0eb5ffa4a0dfddf0bbc0
font_01_sfnt_off0000e496.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE496 12932 bytes
SHA-256: cf7dbd47b63f629bd0834bbf6872e4745b1ecac457485274d71ca3798a22a4d3
font_02_sfnt_off00010ebc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EBC 16140 bytes
SHA-256: 159427b32ed66bfbde86def5e6c2992bde67dfb25400c4000a37c9b59b949b61