Malicious PDF — malware analysis report

Static analysis result for SHA-256 f99df56c1103994f…

MALICIOUS

PDF

75.6 KB Created: 2021-09-19 06:28:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6735083765fd659c8a035a7fb56662b2 SHA-1: 60cc48d97383ea31c2499385194bcb56970dcaa3 SHA-256: f99df56c1103994fc6a5349c944d7d104ba854c28bd21d0111bae6da73ed44b1
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a significant number of external links, many of which point to compromised WordPress sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript and link farm suggest an attempt to redirect users to malicious content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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
  • 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.
  • 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 https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614281a60fce7---raruzivejisefavinofasuko.pdf In PDF document text
    • http://senkyu.jp/webroot/img/files/61723099918.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/xenufoxuf.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/kiperunenax.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210908205048.pdfIn PDF document text
    • https://vicotelecom.vn/static/source/images/file/53741113738.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/jekaku.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/kebomusidigezin.pdfIn PDF document text
    • https://femagnet.com/upload/edu/article/file/jidebumaxakulujozaru.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/a8063b71df363bf6b3e1780db388fdf8/kolasedefotiroziweluk.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/savapixinegefinotuzuxi.pdfIn PDF document text
    • https://copperscraphandlers.com/ckfinder/userfiles/files/68984930558.pdfIn PDF document text
    • http://www.painters-restaurant.com/userfiles/file/wotagurazo.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/3394716110.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd4bb92c69---jusabewojexikiwebusatez.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/nokifoz.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/c2db8d7bbc5804060bba155c01d8f525/92559012192.pdfIn PDF document text
    • http://stoewebdesign.no/userfiles/file/kupagubo.pdfIn PDF document text
    • http://dreamsurgerycn.com/ckupload/files/biranigawir.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/supifufid.pdfIn PDF document text
    • http://scuderia512.com/js/upload/files/74485955650.pdfIn PDF document text
    • http://surmounttravel.com/userfiles/files/95517231084.pdfIn PDF document text
    • https://domilot.com/uploader/files/vonik.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/vuleno.pdfIn PDF document text
    • http://architetturaurbanistica.it/userfiles/files/jigubo.pdfIn PDF document text
    • https://abctranslink.com/ckfinder/userfiles/files/vuguvunaregulafepalonavag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=bleach+brave+souls+orbs+generatorPDF 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_off0000c23b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC23B 10776 bytes
SHA-256: 7ee84d2c02c4261e943865c9821e2795b2cdafca1d886eb534183c1cd2ce76c2
font_01_sfnt_off0000db12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF324 17532 bytes
SHA-256: f311bb76241a7a2ffe1f6d2f9c159ed58cefba07d07c98378d933f0b158a39fe