Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b8287c0a7c7f6f…

MALICIOUS

PDF

77.8 KB Created: 2021-09-12 15:35:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 153de699fd76fa5d6d72a05d8a70bcf7 SHA-1: c2f2d976dd9523709f12354e4668f1ceb28a8684 SHA-256: a4b8287c0a7c7f6fc08bf3342d32d45d260252a823059dd2339295c01cd9918b
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress uploads and disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://archism.ru/uplcv?utm_term=what+are+the+other+files+on+my+android PDF link annotation
    • http://ipmarketing.net/FCKeditor/editor/filemanager/connectors/userfiles/file/sogidolunezemi.pdfIn PDF document text
    • http://refinerlink.com/userfiles/file/bubuxatukotajesobikaxog.pdfIn PDF document text
    • http://halongbaycruises.org/upload/files/36318584688.pdfIn PDF document text
    • http://prime-standard.com/piceditor/file/diporofozeku.pdfIn PDF document text
    • http://foto-preiss.at/upload_files/files/52865957999.pdfIn PDF document text
    • https://ikima.fr/uploads/file/xilalolifekajekawim.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/cdp890kvfipavrv6qp1acr0vgt/10252314350.pdfIn PDF document text
    • https://morabia.fi/images/file/79523872038.pdfIn PDF document text
    • https://bkairconditioner.cloud4demo.com/uploads/files/85701791796.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109111525543654.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f94d0d2d85---49023567703.pdfIn PDF document text
    • https://emartdeko.pl/galeria/file/jubifimaf.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/63969543067.pdfIn PDF document text
    • http://bjyhyy.cn/filespath/files/20210907151505.pdfIn PDF document text
    • https://smobiil.eu/userfiles/files/kepemenogibavimosege.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/namuf.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/wenosolavefatebajab.pdfIn PDF document text
    • http://bigcool.net/webroot/img/files/43834875112.pdfIn PDF document text
    • https://abhimaninteriors.com/ckfinder/userfiles/files/wutesi.pdfIn PDF document text
    • https://www.champagne-cornevin.fr/ckfinder/userfiles/files/42316189207.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/815c69ff9579290c5a1ebeb7b209998e/vunelujuzebi.pdfIn PDF document text
    • https://albertoangel.sinecsas.com/ckfinder/userfiles/files/14803817123.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109031644465449.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_off0000cb31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB31 17516 bytes
SHA-256: 41840dc07fbd1a162208546aca3ecdd12bab6cca58370ba450ae560c5d383dc3
font_01_sfnt_off0000f898.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF898 10724 bytes
SHA-256: 40b3246c32d30a59ff7eb552fb28380defb826477b456144891c8e23996e579c
font_02_sfnt_off00011112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11112 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1