Malicious PDF — malware analysis report

Static analysis result for SHA-256 d833c8a85df96ec4…

MALICIOUS

PDF

87.5 KB Created: 2021-06-29 20:35:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3182a32d87c680c03c2ec9793ea0a1d7 SHA-1: 4d0e4ad74bb08e6ed841a747b3da38e2ad004bef SHA-256: d833c8a85df96ec4f609c8e5599ef2e65e9a913536deb089bed3a70be8c7d063
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to phishing or malware sites. The PDF structure and embedded links are consistent with phishing lures, potentially masquerading as legitimate documents to trick users into clicking malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://smidgel.ru/uplcv?utm_term=attention+deficit+hyperactivity+disorder+in+malay
    • https://butchercurnow.com/img/shop//contents/zuridozudimetukugopibi.pdf
    • http://akkoryazilim.com/userfiles/file/68226020016.pdf
    • http://kulturazebrak.cz/userfiles/remenexagowojo.pdf
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/9a3c74781db1c57d5beba103fc815de9/96864892513.pdf
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7d96f345a---panuvomi.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160844f746ce16---22422998847.pdf
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/1g4acnretdkpg674es4g9i8a6e/dupafevuzo.pdf
    • https://alakharia.com/public_html/userfiles/file/33316344641.pdf
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/52cb6f3dc35a337a3399a5975c70e84b/337387889.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e755e7e2b1---fomev.pdf
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bdbbcac5950---fijotat.pdf
    • http://leaguengn.com/userfiles/file///90250524685.pdf
    • http://brlairport.com/images/file/58159951111.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a0063802d6e---39623198554.pdf
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/20abn8aod6qhl7d10lq4he4hmq/98817172684.pdf
    • https://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/b9c528c43a1651582d967a4d1fff8aef/42617567434.pdf
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d4b5c9407a---55628017317.pdf
    • http://geredekombiservisi.com/userfiles/file/mopusobukow.pdf
    • http://www.thaiboat.net/image/upload/File/58600298303.pdf
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/5ae9a79c6e1f3a67f5cf85a2f04f42b2/40326180532.pdf
    • http://adbuffalony.com/uploads/files/86186806745.pdf
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/ecd9f29a52a5df11f8a74605e9a1cb03/22408642719.pdf
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072e1567f278---zanawavefefaburiji.pdf
    • https://medlineplus.gov/attentiondeficithyperactivitydisorder.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D0 16792 bytes
font_01_sfnt_off00010ae7.bin
c38ecff4f726def3da165aeb76da3c927d1e8b3656a7c6100b832965711fe147
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE7 11048 bytes
font_02_sfnt_off00012474.bin
f64f23f045d746a7f64a463eb2a37ac3f332d9a16a02f477e797e2ec0218de12
pdf-font-stream PDF embedded font (sfnt) at offset 0x12474 16940 bytes