Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbaa39b341ef93f5…

MALICIOUS

PDF

81.8 KB Created: 2021-09-05 17:10:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a518ba791b58cd089a4d5081c3d3bf08 SHA-1: acc55dac5206b4bd8cae2dc4ed89902ab4af80c0 SHA-256: cbaa39b341ef93f5bbc74fd9a0f987888088ef69441525b362365774958b2c9d
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to numerous URLs hosted on compromised or disposable domains, suggesting a phishing or malware distribution scheme. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly imply exploitation of PDF vulnerabilities to redirect users, aligning with common phishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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=holistic+nursing+approach+pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/as0bil4d2av4bscmv3ijc9vvoe/95315354769.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/16111d35959082---tesexoduvuw.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c25447f56---vojuvibigitinilemoxogani.pdf
    • https://fetogram.com/images/upload/files/resadadoko.pdf
    • http://meteosputnik.ru/userfiles/file/48986362740.pdf
    • https://cuacuonbentre.com/upload/files/gutuzusedesorujoso.pdf
    • http://donghocitizenchinhhang.com/uploads/userfiles/file/70387782448.pdf
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/73fb9bcac9e00416652df75a0c1cf382/gizobego.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606c98160e69b---totifeso.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16086e318ca15a---motemitadijezifi.pdf
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/e06497ebf0d248c866e50d2ddc101f55/xegegidubok.pdf
    • https://kuraniterbiye.com/resimler/files/winoniru.pdf
    • http://cosmikkino.ru/sadm_files/23194628808.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d58716f09d---rizufomenexedixo.pdf
    • https://bjjewels.net/nbloom/fckuploads/file/kosorajexizizopanuxuve.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ceb1543782c---50411005890.pdf
    • http://www.boldino-hotel.com/ckfinder/userfiles/files/dalezekugux.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffe73537b1---37697787713.pdf
    • https://panama4d.com/contents//files/92092457368.pdf
    • http://originalcheck.it/public/img_admin/file///zogexawajexeg.pdf
    • http://mountcalvary76.com/clients/9/90/9062e1c9f2360b2cedac6e2854879500/File/betuzuxep.pdf
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/dezum.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e92f5020071---devarat.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_off0000dbcb.bin
fa35905753f991542dff63bb40288a51505200692eccd6b5833f13dea7e3c423
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCB 10860 bytes
font_01_sfnt_off0000f490.bin
f1be1fa23dbc8288ec4066c4229214d4ac97409af7ac71f157da12387028949e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF490 17324 bytes
font_02_sfnt_off0001214a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1214A 16792 bytes