Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38d744decf72666…

MALICIOUS

PDF

89.6 KB Created: 2021-08-18 13:36:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c158611825529d92553922207c33bcae SHA-1: b1782c1e295b367819bb1289dadf3fb9d5db37e6 SHA-256: a38d744decf726661491e3e2dd2437a977ac7e7acd15bbfa8cd5a7a171f1e14c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The primary attack pattern involves directing users to these external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://thegioibaobicarton.com/Images_upload/files/51751997747.pdf In PDF document text
    • http://aarogyamedico.com/userfiles/file/gapotonemog.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609683049baff---49760074208.pdfIn PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/88bba16566a4768842e081bd42d625da/42938515151.pdfIn PDF document text
    • https://rivaflo-south.in/userfiles/files/2786830528.pdfIn PDF document text
    • http://npxbyy.com/wang3_3_10_27/Upload/Upload/file/20216920243617.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/706824ed169fbbdec1e8a36305f93d8f/61278451169.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/84bc05537cf6d4b537d953789f862af6/98988478427.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d423944f0b7---fozetizitatekegelojugoji.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/61270417640.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/japovimagipelipar.pdfIn PDF document text
    • http://sobsai.com/ckfinder/userfiles/files/gexik.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/14544918130.pdfIn PDF document text
    • http://etrustmi.com/ckfinder/userfiles/files/buluxasonixiviliwusumap.pdfIn PDF document text
    • http://accronline.com/userfiles/file/22911938693.pdfIn PDF document text
    • https://ovalpolycoats.com/media/42530630891.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/v9au5l6lhdit0uq88nv8ipemva/64475944082.pdfIn PDF document text
    • http://stopguepes72.fr/userfiles/file/25845708540.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/325e4aec5eba5586dad1c242d5bdbc64/wukakopege.pdfIn PDF document text
    • http://altinay-law.com/images/file/pojefevifajivimubesaliz.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/ca399303e76fe213af4d5989b2bd5fa5/24259662402.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160a531c0367d5---sumowibabujufijudatizu.pdfIn PDF document text
    • https://ascinfratech.com/clientprojects/trading/file/zabatok.pdfIn PDF document text
    • http://chronicles.ae/userfiles/files/milalibegogijonaxeteni.pdfIn PDF document text
    • http://airholic.com/UpFiles/WebEditorFiles/file/rejokimilogawura.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=teor%C3%ADa+musical+piano+para+principiantes+pdfPDF 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_off0000f4bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BC 10904 bytes
SHA-256: a409926f5d1cdc8b73a5ddcb68d7d548ac7c192ebca7f42d3e658af7b3f89fc5
font_01_sfnt_off00010ded.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125FF 18684 bytes
SHA-256: b3e628d5eec7f056e8cab01fc64f9aeac4b21d4c500e2c1fc7d0187017069f25