Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a67ad5c9aed41ca…

MALICIOUS

PDF

77.5 KB Created: 2021-06-15 12:28:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 1228e822e4378a3cf9d7d79856a0ad51 SHA-1: 7e19ce00c52280a04aaa804ad734f6010dfb9e18 SHA-256: 1a67ad5c9aed41ca4d2d05fb43756410fec40f191810ca56d2fd661449349da5
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to compromised WordPress sites, suggesting it is part of a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded URLs and the nature of the heuristics point towards an attempt to exploit user trust by presenting a seemingly innocuous document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krisoc.ru/uplcv?utm_term=prefix+suffix+root+word+worksheet+pdf PDF link annotation
    • https://rockyshairsalon.com/wp-content/plugins/super-forms/uploads/php/files/sung9ce4l4jlmra0mns7l3r8sd/busupi.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/7ouaf40ok78a40d5q95181ldkn/31265640914.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160703edee578b---77120329709.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075983630a44---7111027136.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffebd6a56f---faxiterutanedak.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16082374c2640d---xewowe.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3254d150ff---lixuzetirafobuloxel.pdfIn PDF document text
    • https://akbaturgame.com/calisma2/files/uploads/29110492517.pdfIn PDF document text
    • http://blueyee.com/upload/file/151511227642.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/hh33a4hn53mgbgnns8h5eum4fh/93835057017.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/bd94bc9df1d56d999927fff81e52f82a/40800595942.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/54052371002.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/838b0593cea7be595da2865f5e532d59/16422862491.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab101c0e18e---lopob.pdfIn PDF document text
    • https://mednet.mk/public_html/upload/userfiles/file/23975618958.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
    • 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5A0 4888 bytes
SHA-256: d5b2624e3480e52fd473eacdf1b34fca2990d8eba0bf595c72f9648e25448266
font_01_sfnt_off0000f668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF668 10648 bytes
SHA-256: 00f3a0b5f99cc3a0d2344afc5cce457dc562ce7ff9e7481ccb9f805e86bcca8f
font_02_sfnt_off00011a9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A9D 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e