Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b52166063a8c018…

MALICIOUS

PDF

81.5 KB Created: 2021-09-14 07:15:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 41fd9519226de8710a55263da529c245 SHA-1: 3b55a863c0238fd5108613d088434e5ac4d1f952 SHA-256: 8b52166063a8c018c5c641bcebd011c194405cdf72342c4f136bb5d53b3b3057
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for executing malicious code within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chcial.ru/uplcv?utm_term=nerve+pain+shoulder+arm PDF link annotation
    • http://gdlejia.com/uploadfile/files/20210905_131045.pdfIn PDF document text
    • http://cke.hk/userfiles/84853587637.pdfIn PDF document text
    • https://war-old.its.vn/new/userfiles/file/wefadogetolene.pdfIn PDF document text
    • http://careerpathrecruitment.com/swapscan/app/webroot/js/ckfinder/userfiles/files/56076007858.pdfIn PDF document text
    • http://om-ar.com/userfiles/file/67596182899.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/88910779910.pdfIn PDF document text
    • https://hoavily.com/uploads/files/68435470289.pdfIn PDF document text
    • http://qataminational.com/uploaded_files/userfiles/files/14385683901.pdfIn PDF document text
    • http://pinzimoniofiumicino.eu/userfiles/files/povusamaki.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/62850440365.pdfIn PDF document text
    • http://jawarakreasi.com/file/43823899871.pdfIn PDF document text
    • https://kozlovka.mebel18.com/uploads/files/14034965357.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/kuvadijojuge.pdfIn PDF document text
    • http://www.agot.pl/upload/file/fijis.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16130f9f98c129---71268572910.pdfIn PDF document text
    • http://carsonpokebar.com/uploads/files/5521369045.pdfIn PDF document text
    • http://decaldankinh.net/upload/files/60605000305.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/47935455934.pdfIn PDF document text
    • https://helicopterleasingservices.com/userfiles/files/jexewakoke.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210912094504.pdfIn PDF document text
    • https://altinhediyeler.com/calisma2/files/uploads/80893793723.pdfIn PDF document text
    • https://27061010.com/uploads/files/202109051416507089.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/40653889988.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/44224710981.pdfIn PDF document text
    • http://deltools.com/userfiles/file/virepasekixotanalogowawo.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/dariwivatojaxavipiwidawi.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_off0000d9e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1FB 18440 bytes
SHA-256: 5b8bd6434ddb1475b2e1ff7b957cf258d339f8bfd19364c9522d53645f6a2b5e
font_02_sfnt_off0001207a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1207A 10700 bytes
SHA-256: e56f7a7b7fb1f0e4701b66dbb0c2bd8d482493771aa48776f425a5740082c97b