Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8ee82ad77fea80e…

MALICIOUS

PDF

83.6 KB Created: 2021-06-25 12:58:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: e67787e65e8d49107b39a6369ae7b0b2 SHA-1: bb4c8f4519c6a8deae04199a7780340371570c40 SHA-256: c8ee82ad77fea80eda08d609fc030ae6c5fad2b239797a72bd795bc943a4449e
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to compromised CMS upload storage and disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these redirects. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/kln18m69ge7ji9k04iah6jibuh/sezanezufipomituwat.pdf In PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6a88ed5bb---kixodatinimofixumupomuza.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/27320882552.pdfIn PDF document text
    • https://churchofgodinjamaica.org/app/webroot/files/40334410211.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/62063164586.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085977c4d172---16019307934.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/igediro.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160aa4857733c7---kamuj.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160963da3527c3---78974827106.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab15dd8c6ae---52069887245.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/73181519074.pdfIn PDF document text
    • http://airholic.com/UpFiles/WebEditorFiles/file/lakadupa.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983a262e662.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/17484986124.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16080b58e7cff8---puzik.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/86349834989.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/voxaxaviwe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=connecting+backend+to+frontendPDF 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://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_off0000e1d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D0 17324 bytes
SHA-256: 5d79277637087e852ff7fea9954d5823dd6160254606230b1611c38fe6dc6a3e
font_01_sfnt_off00010f48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001275f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1275F 10700 bytes
SHA-256: 45a18001b01d0548cce9868112626da6193677d46a659bddd10a3e98b3497850