Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8d944911f929192…

MALICIOUS

PDF

79.6 KB Created: 2021-10-08 02:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f8ffd62852db5469ed6e532f19a449a7 SHA-1: 62463480cb60e1f7a8fe31511ffd8ff172bf23bc SHA-256: a8d944911f929192f6118ee4e4f468459f3a55a91d5d64d845cf124c57889fc5
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript and numerous external links, many of which point to other PDF files hosted on various domains. The presence of a 'download button' heuristic and the ML classifier's high confidence score suggest a malicious intent, likely to trick users into downloading further malware. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://www.yemany.com/yemfiles/files/kubakedifevevunobitibov.pdf In PDF document text
    • http://se-ty.com/uploads/userfiles/file/fatepafopeduxavosi.pdfIn PDF document text
    • http://morebricks.com/ckfinder/userfiles/files/sulolitanegiput.pdfIn PDF document text
    • http://goldmustang.ru/files/files/situj.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/84812174616.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/loriri.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/pijitewoxes.pdfIn PDF document text
    • http://architects-desk.com/uploadsfile/pafewemiresowikuz.pdfIn PDF document text
    • http://slxiang.com/v15/Upload/file/2021929748319693.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/nefudiruzesoj.pdfIn PDF document text
    • https://aarushimukhwas.idealviews.com/userfiles/files/87076868014.pdfIn PDF document text
    • http://shiinamotors.com/js/upload/files/25758898835.pdfIn PDF document text
    • http://moscow-vernisage.com/files/files/18477673089.pdfIn PDF document text
    • https://matricula.arendic.cl/files/9563158345.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/8811269420.pdfIn PDF document text
    • http://abwingscolley.com/uploads/files/vavotazub.pdfIn PDF document text
    • http://euromarkcreations.com/new/fck_img/file/38883449888.pdfIn PDF document text
    • http://jarauwerdaenzn.nl/userfiles/file/zedagebojipovekakixetiro.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1615a8a0c874f2---jesonurukolugejaranug.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/65769971234.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141eec8a3fa1---japesogara.pdfIn PDF document text
    • https://sportuna.be/ckfinder/userfiles/files/53311821950.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=sec+114+evidence+actPDF 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://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_off0000d1a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1A3 18452 bytes
SHA-256: efd4c6fa38a9cd0a2905d3387b9d01403d0bcab984cf57167230cfeacd485396
font_01_sfnt_off000101f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F3 10200 bytes
SHA-256: b7c1009182b6a29f4beb8ef1db7ef7181e0dde7bfdf71627800464439a4c08fc
font_02_sfnt_off00011913.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11913 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1