Malicious PDF — malware analysis report

Static analysis result for SHA-256 9403b61e275a6ca8…

MALICIOUS

PDF

124.0 KB Created: 2021-06-19 08:03:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: a23707a5beeb8bd5f854d74473502acc SHA-1: 8b8850e6467151c28632efb35a852349d854ba4a SHA-256: 9403b61e275a6ca83f314ae940fa31b9157468d8b66a32e8625c4c15de9392c3
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/da57188d69abb836124776fbe0275693/sevulituwenidefefiwigite.pdf In PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/7836f926121e412045a64a0c7a2b0e1b/tesuvovisi.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609918c2bdb83---resavibedo.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/ai8jq3k3f0et2cehmgs237ou97/36264506818.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/b707e12543e51083a6ca883733548ad2/newir.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160790a2758c3e---laxenipomutidujope.pdfIn PDF document text
    • http://bagiez.com/userfiles/file/54331750964.pdfIn PDF document text
    • https://aashianarealty.com/file/dotigaxod.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b83c45be68d---walijazakijizosinekikened.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16071854a3b7f5---jomozosa.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/ec7574a45766556fd7637a04a107d628/13773983431.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/79809ca4bb83d70bc92132db3ca3cff6/95498520678.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ace43dbae---tejirakurexabofuwurize.pdfIn PDF document text
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/tekofozep.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2b3ff163d---6558777299.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/33698589060.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091496581678---60015565055.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfdc501696---zigazofokunidok.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/c7f7305bbb81f4db4cd9ad3e3c44a5c8/kapuguwulusepobiraxud.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=movie+xy+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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16992 8060 bytes
SHA-256: fe4bb221e0a9513b87b70bc7cb3d32bf8291ba3891e82683a0cf61336583a081
font_01_sfnt_off000184a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x184A3 4408 bytes
SHA-256: 23b1857497aba48752543a482ace1342fc957036c13c8bdf504c4e26fb993976
font_02_sfnt_off000193b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x193B5 12660 bytes
SHA-256: ff5eb2a01f979d30ed97c276befdd2cfc9713f828e453dbdf19bf426efd41c61
font_03_sfnt_off0001bebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BEBF 16164 bytes
SHA-256: ead7fd593d7f5feef6f283420e9b55f8fa4552f107c64b0063d474dd3355abd8
font_04_sfnt_off0001d3d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D3D8 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333