Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5529a4e837b3ab4…

MALICIOUS

PDF

75.2 KB Created: 2021-09-23 07:47:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bb874e7997c3e9851cc6ff9602e22591 SHA-1: 1090729bccce730e0a89e1f5ca5c208224b9ae63 SHA-256: f5529a4e837b3ab4d267a9e4c5de95d847a52c5dcc457d51b167daaaa35cf04a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. Although no scripts were extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://www.dooleysnaturalgas.com/ckfinder/userfiles/files/fugezoguwuj.pdf
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109181414499039.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5a27c3937---duwem.pdf
    • http://auswallendorf.de/userfiles/file/13038758774.pdf
    • https://www.tahitotfaluovodak.hu/ckfinder/userfiles/files/87310231209.pdf
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/28497047525.pdf
    • http://sumisaedu.com/FileData/ckfinder/files/20210921_7F63C31B18F67F8F.pdf
    • https://artenika.pl/fck/file/buwuzosos.pdf
    • http://k3projekt.pl/uploads/userfiles/files/megefafotawuzo.pdf
    • https://skatrip.com/basefile/skatripcom/files/ramemuwexaferufege.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/09296bf405e2d02578b8cece0d379219/gunisuvoxavoliw.pdf
    • http://partiaweb.com/upload/files/finuzupekiwutotapofor.pdf
    • https://www.iieng.org/editor/ckfinder/userfiles/files/1554965605.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16145ac191a032---7205570355.pdf
    • https://www.educazionesessuale-scuola.ch/ck/ckfinder/userfiles/files/23869443503.pdf
    • http://julianina.de/upload/file/kavugusivot.pdf
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/78342246283.pdf
    • http://abwlargo.com/uploads/files/notovavubewepapiforoxujet.pdf
    • http://rgn2u.com/userfiles/files/24392504365.pdf
    • https://csp-pub.com/stockages/files/79156558410.pdf
    • http://fli.edu.mn/ckfinder/userfiles/files/beferikawivas.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=derivative+of+e+power+xy
    • https://rt9.rspo.org/ckfinder/userfiles/files/40547198397.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c3d4.bin
c50a1d9f77b9209631f082df7ee4ed493bc3ef74d14c30ba424c6c097b1f38ca
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3D4 10400 bytes
font_01_sfnt_off0000db9d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB9D 16792 bytes
font_02_sfnt_off0000f3af.bin
21b70baf3a311512823ffb45869ac3d57d0bfc525ab1d9c844e6f6e5655a514a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 17044 bytes