Malicious PDF — malware analysis report

Static analysis result for SHA-256 55ced9ea961f66ff…

MALICIOUS

PDF

70.4 KB Created: 2021-09-26 18:03:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 98b203a5682901f6143af50ad89af8fd SHA-1: 440a6e0ba766fa113b1d9b2e64cb8a7682dcbbd0 SHA-256: 55ced9ea961f66ff3bd068b88ab2154fd96e4a4258514014c5e23f103bd77837
156 Risk Score

Malware Insights

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

The file is a PDF that contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories. Heuristics indicate this is a link farm designed to redirect users, and ClamAV detected it as a phishing trojan. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://m-s-g.ru/userfiles/files/subujumaxeruzoriwuji.pdf In PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/zegunex.pdfIn PDF document text
    • https://euforbiabulgaria.gbinvest.net/uploads/pages/files/bajukazivagib.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6b3af14c0---dopusapugapodotifub.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b325deb31e---wemazin.pdfIn PDF document text
    • https://securitydm.eu/slicice/file/pifevibegi.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/5731795719.pdfIn PDF document text
    • http://eotp.info/sites/default/files/fck/file/2465996584.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/zinitijegigulinuluzaze.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/032cd3pqghotel0gqpfqko3973/zikebunorebisebuxuza.pdfIn PDF document text
    • https://ikincielinmak.com/upload/ckfinder/files/jojozivowil.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021092217205573499.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/32271241816.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/97448916808.pdfIn PDF document text
    • https://comillaspostgrado.es/userfiles/file/sekosokipu.pdfIn PDF document text
    • https://sadhankendra.org/erc/media/18260045537.pdfIn PDF document text
    • https://palet-school.com/files/files/274970231.pdfIn PDF document text
    • https://tdemo.order-pro.com/ckfinder/userfiles/files/rokurowaxegapajir.pdfIn PDF document text
    • http://moestuinwebshop.nl/userfiles/file/wuxirosagavekevawotafug.pdfIn PDF document text
    • http://poongdung.com/FileData/ckfinder/files/20210916_A19D5730A2ED2BEC.pdfIn PDF document text
    • https://bimore.vn/webroot/img/files/53032598438.pdfIn PDF document text
    • http://hagelkonzept.de/userfiles/file/mibubikixebofeje.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/16996369274.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=camfrog+pro+modPDF 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_off0000b3a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3A7 16400 bytes
SHA-256: 3256195d9de25c855e4be3573de53a55b13126f61edf51f515a8d85e54535d38
font_01_sfnt_off0000dd51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f568.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF568 10232 bytes
SHA-256: fc66276a90b98605c7d6a172ba74c80f670f0bf54e904f49e2374e0c4346745f