Malicious PDF — malware analysis report

Static analysis result for SHA-256 3965bfa23fe6a1d5…

MALICIOUS

PDF

73.6 KB Created: 2021-06-14 03:50:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 10443d14105a22edd2f31cdce764f1a7 SHA-1: e5a73b1bb10fad72b108328f1e45b862c6a46f01 SHA-256: 3965bfa23fe6a1d547d46eac69a1f9d0f74dbe68322bf1e07da4f9b4bd803e65
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 0.9239

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://smidgel.ru/uplcv?utm_term=biology+of+plants+8th+edition+pdf+free+download PDF link annotation
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/5chapipou5if1n0dcukgog9m20/mojofoforip.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/61371818604.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0bc8661cf8---narapukufugusu.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160a018c582295---xipimuponape.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16082299faba5f---16559547297.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a82fc20f8f0---goxoxa.pdfIn PDF document text
    • http://berbun.com/user_img/file/jokixolonirop.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/49mqkr5o7he6u5682o56q7aeak/48924917204.pdfIn PDF document text
    • http://innotack.com/userfiles/files/basetonumasawubuvosagam.pdfIn PDF document text
    • http://sampsonancestry.com/clients/d/d9/d9bd9208c4e45de01aa31840e3a8c66b/File/rededowesew.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/404dd47de16b35214bb62b2558ea8633/49686523851.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608c341bcf0fd---73056997637.pdfIn PDF document text
    • http://altinay-law.com/images/file/xerefirepawas.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609449548d993---mavabuwivivogusorufotovav.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/pc1a42cr3a64g8jcknovthkdrm/libunabudijejawis.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/160926e2c80c9e---81231928526.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/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_off0000de35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE35 5528 bytes
SHA-256: 4fddb99202dc1175ea7f409363f8f9c35c8d8dd7f09f1fcfecc96fb7f4873b19
font_01_sfnt_off0000f107.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF107 10692 bytes
SHA-256: 46edbabbbfa0e9a2b26b83da0341df005089f7a71ec8cac9c1ff00e55f4e4f30
font_02_sfnt_off000115be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115BE 4324 bytes
SHA-256: 7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71