Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd118e3c511693e6…

MALICIOUS

PDF

74.8 KB Created: 2021-10-05 03:48:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 221f8004e7b6e3f4272c79029422170d SHA-1: cabe4e45c23d3efd1a398eba0039db58b9b8c1cf SHA-256: cd118e3c511693e6693b3ccda0125eedcf1a91cc32f8ffbfe8604de738cb6baa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://medvor.ru/uplcv?utm_term=body+pain+after+cesarean+delivery PDF link annotation
    • http://pc75.net/upfiles/file/1632916114.pdfIn PDF document text
    • https://friendsofmultisport.com/ckfinder/userfiles/files/vomutevarugivogit.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133bf051a7bd---baluku.pdfIn PDF document text
    • https://efsanepin.com/calisma2/files/uploads/lorogagikijapozolasubirip.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/dijelunudokalexekulutiz.pdfIn PDF document text
    • https://gozdekadife.com/resimler/files/96006802252.pdfIn PDF document text
    • https://subded.org/userfiles/file/58162286569.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/pejedesit.pdfIn PDF document text
    • http://master-vin.ru/files/file/pijiziles.pdfIn PDF document text
    • https://support-trevianum.nl/userfiles/files/58687667413.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/negisegud.pdfIn PDF document text
    • http://lacasedescaraibes.fr/file/xurapularevemedixupivonir.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16134192ae23a8---8762975527.pdfIn PDF document text
    • https://vyrukrc.lt/userfiles/file/robavazepalizogisuwinole.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/19349794587.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/jokoli.pdfIn PDF document text
    • http://xn--80aafbjcazdrhzgiddbbcsg4l.xn--p1ai/pict/file/jusujenegagipe.pdfIn PDF document text
    • http://cgemfoco.com.br/ckfinder/userfiles/files/25627443155.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/24793890668.pdfIn PDF document text
    • http://cudicio.it/images/file/67806355622.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615213e7620cc---22479418728.pdfIn PDF document text
    • http://koppeika.ru/userfiles/file/zarakekusesiguxujisumom.pdfIn PDF document text
    • 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_off0000bf21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF21 10848 bytes
SHA-256: 5567d96fa6506477d00ed519fc03955041341dbfaf043d82caaac4c13a3dcb7d
font_01_sfnt_off0000d85f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85F 17564 bytes
SHA-256: b78b246a51405ad783ef88fd6cf94429b98aa8ba89205df4ab0ebbe78aa3b80f
font_02_sfnt_off000105ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1