Malicious PDF — malware analysis report

Static analysis result for SHA-256 43ff16c58c68090c…

MALICIOUS

PDF

77.0 KB Created: 2021-09-17 04:26:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5f66020f5bb877c9851afde09a7f35a7 SHA-1: b89c3c9a2a046cf3cba0112ce10f9c9df196355b SHA-256: 43ff16c58c68090ca04b29298deb7e7b9834e91dabf7e7445c9a9792bc14635f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect users to malicious content, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://aihyang.com/userfiles/file/14013319780.pdf In PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec40190286---libukidenazemezu.pdfIn PDF document text
    • http://zkqzl.com/uploadfile/file///2021090819431369.pdfIn PDF document text
    • http://kmsenior.org/file/files/52009812540.pdfIn PDF document text
    • http://svenskafik.se/uploads/fckeditor/file/45855243303.pdfIn PDF document text
    • http://svarovani-tig.cz/userfiles/file/lalut.pdfIn PDF document text
    • http://joomlacode.org/fckeditor/editor/filemanager/img.php?file=file/99767985374.pdfIn PDF document text
    • http://smirna.pl/files/file/26893616693.pdfIn PDF document text
    • http://huthamcauquanggiap.com/upload/files/10395747545.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/01f291df6b13ba88fba66af3e9fd67f3/30151242432.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/nerujivel.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/kuludelijajonone.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143dc1e9f26e---57163870219.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/9878d0d917ce6bba9a1b1deefdd2ca17/73272203872.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614006bccae15---58702282332.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161333bbc1fa82---nogijewujesozejupifo.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16142902779555---fipoxorivilawafafepa.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/lumorenipesarewigumexudon.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8bb773ff7---wiziden.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/161389c4ade76f---58132370017.pdfIn PDF document text
    • http://ttccid.com/userfiles/files/46729617888.pdfIn PDF document text
    • http://cutyoursupport.com/userfiles/file/6028597759.pdfIn PDF document text
    • http://idealhca.com/admin/images/file/rijafalarusi.pdfIn PDF document text
    • http://squash-fitness.cz/userfiles/file/67909848842.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/zimodavevu.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613f74f68f901---xekewunaxebaneboderav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=q18+smartwatch+software+updatePDF 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_off0000c4e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4E0 17968 bytes
SHA-256: db7d46a3cc0aa499e332f27b82913af78647e3ddd34fc06e78b05e456da06fd1
font_01_sfnt_off0000f3dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3DC 11148 bytes
SHA-256: cd39d820386be1f69f525ea72d33e38e423bccf6ecaf4ca466603e3197422427
font_02_sfnt_off00010e24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1