Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0e5459af15aad9f…

MALICIOUS

PDF

70.9 KB Created: 2021-09-13 09:45:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2a09e4655971723e024367cbcaa56e9b SHA-1: 7f7f25d883d52c3ce572da73dcc0106ba5989d55 SHA-256: a0e5459af15aad9f793dde4e2e62dd09698ae67553004682cf2ccf44213fc72d
156 Risk Score

Malware Insights

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

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, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dxqzx.com/ckfinder/userfiles/files/20210910_200206.pdf In PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/dedurafekogaxovaken.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/20996410157.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109120847406777.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/jidukigakajagomeluju.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f9ca252fb---65958990901.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/161368472c5a14---37771815815.pdfIn PDF document text
    • https://toyotaautobody.com/ckfinder/userfiles/files/95980184978.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161326328ce555---13487604440.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/1735743248.pdfIn PDF document text
    • https://alwillislifecenter.org/ckfinder/userfiles/files/11632836842.pdfIn PDF document text
    • https://eastmangroupllc.net/ckfinder/userfiles/files/14327943580.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/13155812045.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131094905faa---gimodawemeka.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16132e1ea2c291---lineriwemufidin.pdfIn PDF document text
    • http://www.emploi.nat.tn/ckeditor/ckfinder/userfiles/files/6873338827.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/valogupokerubonimad.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132e280e389a---51095839817.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9e129d97e---tomevodomizakujilokaned.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/73809625261.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210903050652.pdfIn PDF document text
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/5169344094.pdfIn PDF document text
    • https://pfollowers.com/ci/userfiles/files/jepupesubulojo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=auto+block+calls+androidPDF 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_off0000b5ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5EF 10544 bytes
SHA-256: c7f5b04f1dee4c343c4ef2a89500f853cc6fdf7bddbe2d89b5bfe5e85f80faec
font_01_sfnt_off0000ce1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE1C 15528 bytes
SHA-256: bb845917ddf893353f37a6089347f559dbeec6a1c361386cf00c02db56bfafa8
font_02_sfnt_off0000f5ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1