Malicious PDF — malware analysis report

Static analysis result for SHA-256 87339ca15b63487c…

MALICIOUS

PDF

66.0 KB Created: 2021-06-17 01:19:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 81a6d8686431dca26e3f808839270f1b SHA-1: 4a490e67fe2e67dd392255afc3791bf235e81da5 SHA-256: 87339ca15b63487c83ace7060b06cf68f0b8aae2b344995644a54e12a3b7ab70
156 Risk Score

Malware Insights

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

The PDF file is detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external sites, many hosted on compromised WordPress installations, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains references to 'Autocad electrical 2017 tutorial pdf', likely a lure to entice users to click on the embedded malicious links.

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://inwebjor.ru/uplcv?utm_term=autocad+electrical+2017+tutorial+pdf PDF link annotation
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/b23928867e6b5d046f27d63de3c5b426/sasukonawenexogakuxivuzi.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d23451fca---wekir.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/5778413163.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b2d165af4a---wepekoz.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bb2cc2d95b5---17519960107.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607de031483bb---66018851886.pdfIn PDF document text
    • http://zzliuxue.com/upfile/file/%5C/19447947327.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/e5e4a3eb27afe35de9b952b44d6f9903/zulavixajerutefiwebase.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a736a70f201---dozopawajudotobedidado.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608ba93795adf---fevixomibamalebotex.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/68125743558.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9b75db667---12010214417.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/xasuluz.pdfIn PDF document text
    • http://oryginalnedekoracje.pl/userfiles/file/10761138860.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/1a490b57f09ca3ab2275f7e4be9de081/11393934113.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/bfa9456580a03cd1bcd1213bcada7504/bowapokij.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off0000c809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC809 5364 bytes
SHA-256: 59a04b02d0ddece8566f9c98e9e05f85cbe835b0cfaf076f0f26bf1812ef682f
font_01_sfnt_off0000da64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA64 9432 bytes
SHA-256: 27aa5c01a5caf1a2380bae939c302eacd9340241cde452228b72dc1d494e08b1