Malicious PDF — malware analysis report

Static analysis result for SHA-256 89e30cde5aa5a8b5…

MALICIOUS

PDF

74.1 KB Created: 2021-07-02 14:56:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c6dfe0d02c31942d5699033263619517 SHA-1: 2637725701dfa16d448a90dacf8509c4c4b823c1 SHA-256: 89e30cde5aa5a8b5d900be3b6f11cb4ebe93668e7b5d90391c45545e0bb8ffa7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was identified as malicious by ClamAV and an ML classifier, and it contains numerous links to external PDF files hosted on compromised websites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm structure, and the PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristic points to the use of compromised WordPress upload storage. The presence of these elements suggests the document is part of a campaign to distribute malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 http://joyear.com/ckfinder/userfiles/files/vifozuwenesoxarizajade.pdf
    • https://olterus.com/contents//files/24314596179.pdf
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160bedcbb0f08b---98717028778.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160affa8d65fba---salavamowip.pdf
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0437824563---rorebene.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d99d3038326---91985024335.pdf
    • http://www.alex-vasilkov.ru/images/wisdom/file/menok.pdf
    • http://abnicum.com/files/file/vewepamaboxofufoxukorixe.pdf
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/ureqk2e7bhb24r130e6m34fe54/86395402903.pdf
    • http://cesishotel.com/res/wysiwyg/file/56767810152.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/e58ef267d3045d962f2b1a06290bea6c/33194252708.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c4a5c98c651---vuxifovofeterezarozezi.pdf
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16083072e357af---tiwuxatajudoref.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160918aea549eb---zifabepawun.pdf
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160743f43a51a7---58550996045.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c425b738e0---71018598105.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607e74fac108c---92787408989.pdf
    • http://lev-steklo.ru/userfiles/file/29489608128.pdf
    • http://alexlunacoach.com/img/editor/file/nivojeb.pdf
    • http://dancingstarsgreenwich.net/clients/1/10/10f73e4104fe6082999c9b722aa65ba2/File/21581265703.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c795bfcb3ec---jasixabibisikesapikula.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=red+and+green+together+make+what+color
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1f6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC1F6 16792 bytes
font_01_sfnt_off0000da08.bin
0fd06a97dce9f708b1a40a193c8131e81276ce3974d846ce7636d13b3fd5e7fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA08 15808 bytes
font_02_sfnt_off000102bc.bin
e58442beb7dfe155e942ef75d355e2f217c8a1a2b0ee054d9f3166b8374043ca
pdf-font-stream PDF embedded font (sfnt) at offset 0x102BC 10780 bytes