Malicious PDF — malware analysis report

Static analysis result for SHA-256 99457b8d9670dc20…

MALICIOUS

PDF

73.7 KB Created: 2021-10-01 03:02:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f6f50d4007f0f7d92953cbfd3fe5caf2 SHA-1: 65cd695ad3edbb3d8f546aeb52f8a66fd41184ed SHA-256: 99457b8d9670dc2028f5a5dcc11fc12446aef7ca3f18b36a8872595df8de013a
156 Risk Score

Malware Insights

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

The PDF document was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, suggesting an attempt to redirect users to malicious content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.naabelectric.com/userfiles/files/81733640149.pdf In PDF document text
    • http://bluebiz.kr/userData/board/file/jikubaji.pdfIn PDF document text
    • http://travel-door.com/userfiles/file/59207713303.pdfIn PDF document text
    • http://15881588.com/ckupload/files/22237580148.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136ef857bc53---31160832372.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ffa564704e---dajorumuxopukajemawofuxe.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/bfd46cb4d1b3a2ad364af13233128d2f/jonatage.pdfIn PDF document text
    • https://4cmedica.com/ficheiros_upload/file/rubafutos.pdfIn PDF document text
    • https://szallas-karpatalja.hu/upload/28585857689.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/97628962857.pdfIn PDF document text
    • http://rassadaspb.com/new/files/file/53644320959.pdfIn PDF document text
    • http://tolaniprojects.com/userfiles/file/jalulowu.pdfIn PDF document text
    • https://teater77.nl/userfiles/file/51515023325.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/79529183554.pdfIn PDF document text
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/mugosapew.pdfIn PDF document text
    • http://tai-group.com/upload/files/vafixiludazepo.pdfIn PDF document text
    • http://szjg.hu/images/file/68833248253.pdfIn PDF document text
    • http://ues-rb.ru/themes/ues-rb.ru/files/vularulenawuxavipinox.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/fuvasofitoforop.pdfIn PDF document text
    • http://trufeel.com/ckeditor/ckfinder/uploadfile/files/51697442818.pdfIn PDF document text
    • http://hoachattn.com/image/files/warebedobewarisegivujipip.pdfIn PDF document text
    • https://mannerfeltdesignteam.se/ckfinder/userfiles/files/84022699712.pdfIn PDF document text
    • http://ebrinteractive.com/userfiles/file/90035392889.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/gugezaligafejoxopag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=how+to+add+subtitles+in+mx+player+online+streamingPDF 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_off0000b8fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8FA 18004 bytes
SHA-256: 3ab55185e72309e5b05f8bd314af37d55a976a2b7e36c7788ce024e6e3f8b107
font_01_sfnt_off0000e6b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fecf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECF 11268 bytes
SHA-256: a51ebca090aef0df62229fa543b9f8bb8fae09c6906a2e4d57abba725fd459d7