Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b6bfa9f9240ca17…

MALICIOUS

PDF

82.1 KB Created: 2021-09-20 18:28:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f7682e6c5e52abc0cdc51e9e9b74ab24 SHA-1: 4b80af77be6cd20a7b984b005a1e9eeb4a945eef SHA-256: 4b6bfa9f9240ca17a337ccfbf1ecf024d9262ec141b3851a57f3213edda07faf
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. ClamAV also detected this file as 'Pdf.Phishing.Trojan'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://philabc.ru/uplcv?utm_term=inshot+video+app PDF link annotation
    • https://siahotel.com/userfiles/files/274432796.pdfIn PDF document text
    • https://lexcochoralsoc.org/demo/lccs/beta/userfiles/files/wotivaninixafaxukuwu.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/pupalatukofumopebeparor.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/74896075226.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/47043026540.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/wosolunidepises.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/94706996517.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/uerpukiof8o7v5qrbnib0dpu55/50723031072.pdfIn PDF document text
    • http://sungwoneng.com/upfile_editor/2021/files/gaxagekeduvepozetuwuze.pdfIn PDF document text
    • http://fukaofoods.tw/uploads/files/202109030843224999.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16137b77ed255c---wosomabezob.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/burovosulajawovibexakefo.pdfIn PDF document text
    • http://fnathservices.com/upload/file/6010933974.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/pediroburusuxinofuzox.pdfIn PDF document text
    • https://emenu.hu/editor_up/wenetebositodag.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/file/56942908975.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/sazexupekifak.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/90699632498.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/6dc7fa0k33p99vbrg6tcrbeplr/93268781568.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/zakug.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/gokolamodobidal.pdfIn PDF document text
    • https://tonere.shop/app/webroot/files/userfiles/files/naxopenejivotakun.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_off0000df83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF83 16968 bytes
SHA-256: 08240d32d2d7f76c4e52c4fe806fe10931604635a83bcef42e185214e0d044d4
font_01_sfnt_off00010b56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001236d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1236D 10360 bytes
SHA-256: fb36397f1ece83854ab9edbfd7bd8d84eba38a2c27f5d76e2c4a5ad003f12c50