Malicious PDF — malware analysis report

Static analysis result for SHA-256 953611a6d6e0be15…

MALICIOUS

PDF

73.3 KB Created: 2021-06-14 14:41:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 995ab242c8ab31c90d3ad742ae7df061 SHA-1: b02dfb055ccd157667f7bf99dba3ec24814309a5 SHA-256: 953611a6d6e0be15cc97f2f7af3fa8b0601ee1ab8fb36de456e6fc6f5e910931
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 0.9604

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
  • 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://synerhu.ru/uplcv?utm_term=gta+5+stocks+to+buy+before+lifeinvader PDF link annotation
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/f31f57b6aaee00231fd6f1afd21ca272/pazife.pdfIn PDF document text
    • http://sixtyguildersresearch.com/admin/photos/file/bidekufisijumirifigisabit.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093a71429cae---fenulepuwewuxugadimixa.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609d7587b111f---58024431244.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/fewekuta.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160908cd35d366---48603348535.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608371a027ad9---kivatikekawurenuvuk.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608b88b83c57f---zevuvujufogesuve.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16098678de67b3---93378341507.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/f9b75f5e7b49dac578979ede26cb0e3c/jefobowozenavomusibu.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/aoekh060emopjrplkajl1cenpm/nexalenewijiz.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/3774eee5e1d3c7dddf83ac70dd6acbf2/43857760315.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/51f58f5307dba9bcd1aac30ba9b5c479/nezobirikifuwatomo.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/s0bcast07d1gnccuiq2evg5b37/13438757570.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3F 5536 bytes
SHA-256: 437771233520492354a190a28913918bbfa5eaa2766279d91584d9fee4dd745d
font_01_sfnt_off0000fd3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3A 11468 bytes
SHA-256: 8c716b59393d293080683cca6aa4050ae4bd6bedc6da238637d57066bec818c9