Malicious PDF — malware analysis report

Static analysis result for SHA-256 1360a843b88aa76c…

MALICIOUS

PDF

79.1 KB Created: 2021-06-13 21:45:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 6382f628e4beffa1582129907d91d499 SHA-1: 805c5d35e34004c47b66d978d5d1d9d1f7e6c04d SHA-256: 1360a843b88aa76cd86d29d732b1b6745de1820fb915f867598892287861438c
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • 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://synerhu.ru/uplcv?utm_term=fraction+addition+sums+for+class+5 PDF link annotation
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/e12660a5cb3ff87eb79af95c964f10f2/89447859980.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/3eacb1e89254c153e268ebc142940917/dofefumuw.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/b431b2b8518cc18351ec24854268122c/xepofona.pdfIn PDF document text
    • https://idd.no/ckfinder/userfiles/files/ribabiputaf.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098bc7f593bd---13178650946.pdfIn PDF document text
    • https://angkorphotographyguide.com/userfiles/file/vogugasunebotevufizujuza.pdfIn PDF document text
    • http://allycatering.com/userfiles/72284227771.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089df5dd1b68---53289755451.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/813a41a2af0c3e66250609bcedbbd85a/62624476285.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2464da03a---61733211246.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c73ebeeded---65920686089.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c56db4ebe39---xapejuzifefanete.pdfIn PDF document text
    • https://actorconseil.com/files/file/jozigefusoluroreju.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/93603412420.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a411a807d7---watozajuxumexan.pdfIn PDF document text
    • http://28777886.com/Lpf/UPFILE/userfiles/files/rojido.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_off0000f4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B1 5244 bytes
SHA-256: e0896e051276af014fda6e788c80d20434a094ae1f5c23d7c31d225ff804f3f0
font_01_sfnt_off00010674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10674 11992 bytes
SHA-256: 1997b3771d89460809b1f4558df86baf095de56bfba2bef10efb824cdad5ec00