Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b6a3d6ce5fbdd0c…

MALICIOUS

PDF

92.3 KB Created: 2021-07-19 00:50:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f22bcee2e152a76aeb7a1875bcdcac64 SHA-1: 6e28f97bd1fbb7d2080aecc419ed511893e5f5c8 SHA-256: 8b6a3d6ce5fbdd0c5a8b67117a50b0b08869ed3906774402f27c4d05d6e09fab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains a large number of links, many pointing to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The embedded URLs and the nature of the heuristics strongly suggest an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://myclubowners.com/userfiles/files/50962455524.pdf In PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160aca4fd0ff2c---taxowisinawuxur.pdfIn PDF document text
    • http://jevades.com/aircraft/fckimages/file/16596611609.pdfIn PDF document text
    • https://pelicanfinancialnetwork.com/ckfinder/userfiles/files/linokusiwamogujon.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/43acc95e171ec517b36e8e85ac01397a/89872416543.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/b645ca1a846a78a1e1cf3d14212ea462/dopabatademasolerixoluvo.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ead9e0ae8---86055973814.pdfIn PDF document text
    • https://mrmobilewebsite.agency/wp-content/plugins/super-forms/uploads/php/files/cc486189a7b2563bfa6efe8af8263830/nepujejitikizitowe.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/17865432973.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/sodow.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3d29e0e4ec---xexaxusuvibezefiruki.pdfIn PDF document text
    • https://commonwealthsportsawards.com/userfiles/file/ziwitole.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/gofesewumajemilimes.pdfIn PDF document text
    • https://genesislighting.net/wp-content/plugins/super-forms/uploads/php/files/6280e397b3d2fcd86890e73a281c1fa5/borisaxeve.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/7e0578f3094b6e33ac1f7f8b30bf291a/zanasilu.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160867f58ea24b---96631649465.pdfIn PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/43330108394.pdfIn PDF document text
    • http://safarang.com/basefile/files/54785302424.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/beranudiguvidu.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072834da7680---zusijew.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a788d248659---natejuz.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a30082e3ea5---87879859208.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=sprinting+before+and+afterPDF 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_off00010251.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10251 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011a63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A63 19148 bytes
SHA-256: bd64ed977355cabae76952d01a94bdc56aa210c6173ed3f60ab7e5a912f7071a
font_02_sfnt_off00014bf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BF2 10672 bytes
SHA-256: 28ec9ef73dd75f78ea22ab880bf55e93db0acb23720ee6818087a66c6e68a021