Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a3cb9e3a193d1d…

MALICIOUS

PDF

72.3 KB Created: 2021-09-17 18:13:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6afa6b1f19ae0fd046ecd447fa6675db SHA-1: 59f13f86fed48ea1fad459144c9d95ec64c4f20b SHA-256: 31a3cb9e3a193d1dc44ef0de04467db5cdee279516806f8b41d1a9d20a5eb20e
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised CMS upload storage locations and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of numerous PDF links suggests an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ifap.it/images/file/24473975224.pdf In PDF document text
    • http://hmondo.com/userData/board/file/93384643291.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/86175692193.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/gefatorunosi.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/4b90aadcf6553fc931bec72165026798/witegi.pdfIn PDF document text
    • https://nieruchomoscikomercyjne.co/files/file/28164275775.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/zafisak.pdfIn PDF document text
    • http://playeasypiano.com/resources/fck_images/dibesewemosusi.pdfIn PDF document text
    • http://bajajsports.com/userfiles/file/52320240071.pdfIn PDF document text
    • https://koratspring.com/upload/file/99333913376.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/wawedutefejazaridebapulik.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614314b9df6f0---20552904339.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16140069e7ff1f---32605583513.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/segonazowiz.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/71071471565.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/pogewug.pdfIn PDF document text
    • http://novichiha.ru/pic/file/nagijudirosuzelexusupo.pdfIn PDF document text
    • http://beta-rc.com/upload/files/riraziwupuki.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/9d4aadbb0c19697989a78f7108bb1675/dagusizewakapukerapuzif.pdfIn PDF document text
    • http://360global.ca/userfiles/file/98283859048.pdfIn PDF document text
    • http://thai-apsproducts.com/file_media/file_image/file/nolajorosapadinase.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/17143274671.pdfIn PDF document text
    • http://geomanteia.com/userfiles/files/raretad.pdfIn PDF document text
    • http://myshiou.com/uploads/files/202109101112072427.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=ar+dragon+apkPDF 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_off0000b843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB843 10104 bytes
SHA-256: 66841109b2b956db3c0b42ae3d78f1058be468718739e3244ee27598f5fdba2a
font_01_sfnt_off0000ce9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE9B 17524 bytes
SHA-256: dd652072bcb9ae6b19984e700286a5e01f9f197e11d954382043bd9234e3219d
font_02_sfnt_off0000fbf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1