Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c8a50346cf81dc1…

MALICIOUS

PDF

78.6 KB Created: 2021-06-24 22:54:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: df3c71dff2391167c03c2b36a275bba5 SHA-1: 3cd65bbc6c2fe69813d8078067ccc8ba66c15de2 SHA-256: 1c8a50346cf81dc1360ffb7cfe9de1192de9919296c23a82b3ffaac26bb78c88
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous links pointing to potentially compromised websites and disposable hosting, suggesting a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, indicating it was likely generated programmatically to appear as a biography, a common lure for malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16082343679112---96460409076.pdf In PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/filigusimekubola.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca040461005---roponisimomaj.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/a424d2fec6c6e4401a88553ee4363ad0/95063320564.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16080d6ffe8f9e---xefararutoreduguwefobapu.pdfIn PDF document text
    • http://ghalemdi.com/userfiles/file/dodunofuxoxev.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/fstmgafgc1rh67hud1n40icgtt/99470978462.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1608983cd0f100---9745954920.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/2bef652295a4dcf96a7fd6dffde94d17/momopudogim.pdfIn PDF document text
    • https://horizontire.com/userfiles/file/jowonotalugozufupedira.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071dcf08d386---xepetaxosixadekim.pdfIn PDF document text
    • http://rideco.hu/upload/file/jexatepux.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160caccae6386f---7050958015.pdfIn PDF document text
    • https://sportsht.com/userfiles/file/57323171128.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/42628c0c586a74b1eadd93d99a532e04/31242713584.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/YTWXjIUwRh0/uplcv?utm_term=abu+bakr+siddiq+biography+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f440.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF440 5692 bytes
SHA-256: 00cc8ee45fc9251c595d771aeec88a914cf99b64cd9555eb8b2fdfb31e0b4ddb
font_01_sfnt_off000107a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A0 10808 bytes
SHA-256: 009b3cc15037603e26df9eca6c2926dfc3c8423f215271a5cfb6f406d90ebbdc