Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3fbb0627d04812c…

MALICIOUS

PDF

94.1 KB Created: 2021-09-02 06:09:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cc4a9d07cf2155e6c1f1d9709a2c48d4 SHA-1: 95753cdac5a3cc937a3c3f5bbec58f05fc29fe04 SHA-256: a3fbb0627d04812c0560fdaf9f49cf65d6052171639c77f937e2095874987eb3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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 https://ketchas.ru/uplcv?utm_term=nursing+diagnosis+of+ineffective+airway+clearance
    • http://ecole.ru/text/images/file/82305277386.pdf
    • http://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/etme36v20pn90tv6fe7m9hchn3/15993182158.pdf
    • http://www.catedralirodahaz.hu/data/editorfile/lidaxajasitolivenofi.pdf
    • https://baust.edu.bd/app/webroot/ckfinder/userfiles/files/24162721568.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/e48094a3d65d0a9781bce546475b5056/bipavalinevonenufigekiwil.pdf
    • http://bogaarchitetti.it/userfiles/files/41419288439.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080e5d849607---dizafisusenavego.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16095aca343605---7550812427.pdf
    • https://micsys.in/userfiles/file/wivowufilagapojugajir.pdf
    • https://ijieet.org/ckfinder/userfiles/files/sekewufunekopezo.pdf
    • http://novafish.it/userfiles/files/3402281919.pdf
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/5174dd86a47715ebbc63e71ad4fc9552/mifoganaropew.pdf
    • http://violetstudio.in/userfiles/file/laguzaripejarixa.pdf
    • http://theettiaresmontreal.com/clients/f/f0/f03dfc1790708d0b03c48e9879ef2ea6/File/69573627505.pdf
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be15352a2e2---2444458209.pdf
    • https://luminex.pl/upload/file/75190071479.pdf
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/53663659539.pdf
    • https://profesa.net/userFilesfile/27700074817.pdf
    • http://pileshoppen.dk/userfiles/file/lizawajabewofotabe.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612b439785221---37901320201.pdf
    • http://opersan.com/file/33473665726.pdf
    • http://norilskgu.ru/userfiles/file/7834355003.pdf
    • https://fishuntpesca.it/file/5005321710.pdf
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/o2e51avd8miv42dt22cmj822cj/39993754381.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010bae.bin
dd4f62fdae6b85b9d3db3ba9d81273c57c0a2b4482823704b6130361aa7e1515
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BAE 10996 bytes
font_01_sfnt_off00012535.bin
505481feb38f085fefd91128c20dfe3d83ea9cd349677c4f2258c7fded14c453
pdf-font-stream PDF embedded font (sfnt) at offset 0x12535 17312 bytes
font_02_sfnt_off000151e6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x151E6 16792 bytes