Malicious PDF — malware analysis report

Static analysis result for SHA-256 55f81dc15c8be927…

MALICIOUS

PDF

78.6 KB Created: 2021-06-19 02:22:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: c64852a08dab72d43daf1182f0974f06 SHA-1: 4597565df60a3b6661b2bdac13fb72143ecf214b SHA-256: 55f81dc15c8be92745b5818a3474ee2d1ee5b578d465d42509619d6c4e109921
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059 Command and Scripting Interpreter T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a clipboard-command (paste-and-run) lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. 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
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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://oniceh.ru/uplcv?utm_term=nfs+download+torrent PDF link annotation
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072decfd788a---kirikegas.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd76c50ae43---55671490171.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/32969412581.pdfIn PDF document text
    • http://apcmagon.com/userfiles/favewawida.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/wefivijeretajali.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16099ed4cb0ac0---12771563303.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7823e6290---1542721164.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a9781073422---8987182188.pdfIn PDF document text
    • http://ezibra.pl/upload//file/70431991506.pdfIn PDF document text
    • http://24cvety.ru/upload/files/45580962150.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/3rh45hiknle7bv7q0eprlbspf6/19920713584.pdfIn PDF document text
    • http://canoeing.by/pics/files/24459571543.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a951650b3b1---72619757761.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/7938db803790c097099adabff49a248b/kilodinebexilo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA54 4704 bytes
SHA-256: f3021dd896e718be51f8af742502771a1de6bdf6befe30c3b1aef50f70630210
font_01_sfnt_off0000fa6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6C 10872 bytes
SHA-256: c55d3fac7de763539d1dd9b6840741c0a33ca631a79ab7f27bccef174a13ee17
font_02_sfnt_off00011fae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FAE 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3