Malicious PDF — malware analysis report

Static analysis result for SHA-256 8406fc9ff2e043aa…

MALICIOUS

PDF

70.8 KB Created: 2021-10-02 23:05:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: bfdf2bdf193e98baab96e8e90ece6e54 SHA-1: 24483a28de366f7d8e50e3a469cf9207d3b98daa SHA-256: 8406fc9ff2e043aac2df2cda0e42422e3635124728253da72428aa120c0d2bd6
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload storage and disposable hosting. The document body is unreadable, but the presence of numerous external links suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://cplust.com/upload/serback/files/20211002162446.pdf In PDF document text
    • http://2016.letnifestiwal.pl/ckfinder/userfiles/files/56001039058.pdfIn PDF document text
    • http://canionglobal.com/FCKeditor/file/95139083922.pdfIn PDF document text
    • http://sanzmendia.com/userfiles/files/gaxabazabadomiw.pdfIn PDF document text
    • https://aadharshilaschool.org/userfiles/file/rorejudufuwufoponatoka.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aced8950be---19295634300.pdfIn PDF document text
    • https://shaplaconsulting.com/app/webroot/ckfinder/userfiles/files/bubavewonuru.pdfIn PDF document text
    • http://parfumland.sk/upl/77299540111.pdfIn PDF document text
    • http://thaifilmind.com/UserFiles/file/94809328788.pdfIn PDF document text
    • http://summitremodelinginc.com/userfiles/files/56265584845.pdfIn PDF document text
    • https://lenaoyunlar.com/calisma2/files/uploads/tadaduwidutososowam.pdfIn PDF document text
    • https://kameramuzesi.com/upload/files/41897571960.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/161444c0811af7---novilumojadewuderunagek.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/161499f16d6dac---43338652533.pdfIn PDF document text
    • http://tafgambiatours.com/userfiles/file/sigijixenose.pdfIn PDF document text
    • https://media-get.ru/userfiles/files/215858522.pdfIn PDF document text
    • http://catwalkexotique.com/userfiles/vodogivixinufizezif.pdfIn PDF document text
    • https://deepex.hu/hirek/files/4483068552.pdfIn PDF document text
    • http://gamebonda.com/ckupload/files/2863880782.pdfIn PDF document text
    • https://tavio.ru/files/file/kukufowab.pdfIn PDF document text
    • https://malayalamfoundation.org/admin/my_files/file/kumizipabulopefe.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614bde11a63f3---vuxunavozikedov.pdfIn PDF document text
    • https://jogamiskolc.hu/ckfinder/userfiles/files/2664593283.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9b44e15b3---pizijadoxujelirudoga.pdfIn PDF document text
    • http://paramountswimwear.com/userfiles/files/25142972922.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=network+access+control+pptPDF 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_off0000b503.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB503 10428 bytes
SHA-256: bab22c409215780497b5ba7fbfc55052512452c65fd45e64cb21b4171e29559a
font_01_sfnt_off0000cce5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e4f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F7 15832 bytes
SHA-256: ffb41495a1c574eb2fe4f9db0788dcc062d95c281befa0c4ffd2a38422551d7a