Malicious PDF — malware analysis report

Static analysis result for SHA-256 512dcfbbd93bc54e…

MALICIOUS

PDF

70.3 KB Created: 2021-09-21 15:35:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8ebf88963c27b38fa01b6c5dc72adf3b SHA-1: ff0e28ce0b270e5a34619d173170eb870452ff36 SHA-256: 512dcfbbd93bc54e5aa9dc549fd02b06bcd3ecc587f223ffa0b23a32f3a238b7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chatsystem.site/js/ckfinder/userfiles/files/37479651051.pdf In PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161443d6343339---bubozubogal.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161418428422fa---52337470328.pdfIn PDF document text
    • https://mkycc4.com/kycc4.com/userfiles/files/jisuzo.pdfIn PDF document text
    • http://aggengr.com/uploads/CMS/file/dewabataw.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109010730256465.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/barogiveximaru.pdfIn PDF document text
    • https://equalland.com/uploads/File/mududex.pdfIn PDF document text
    • https://neurondevelopment.org/userfiles/file/99345858959.pdfIn PDF document text
    • http://azinsaghf.com/cache/fck_files/file/70016691413.pdfIn PDF document text
    • http://meghdoothsuzuki.com/uploads/27652702220.pdfIn PDF document text
    • http://suaups.net/userfiles/file/9978145202.pdfIn PDF document text
    • http://annabarons.lv/files/files/737991367.pdfIn PDF document text
    • https://congnghieptauthuyvietnam.vn/upload/files/nijup.pdfIn PDF document text
    • http://ktai.lmg.jp/upload/file/27097887609.pdfIn PDF document text
    • http://prestopc.it/upload/file/43951818114.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/74d1da49197a5e16d03445f6f1b17fd1/kezimuvonefaforovurixivav.pdfIn PDF document text
    • http://luxe-pools.fr/i/File/43803294611.pdfIn PDF document text
    • https://jmcoverseaspvtltd.com/uploads/files/girenijesilelid.pdfIn PDF document text
    • http://adice-area.com/pictures/files/44725509949.pdfIn PDF document text
    • https://avukat.dnsaktif.net/upload/files/dujifofuwulisikumufe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=nfc+tools+pro+editionPDF 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_off0000adb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5C6 18232 bytes
SHA-256: 1af8dea855a96eb66c009eead42f06be85bc6393dc9754b07d035bc50ca55514
font_02_sfnt_off0000f47f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47F 10428 bytes
SHA-256: 42bd776f4e3876afa35d5b603f9a2788162168c2871f3ebcd9041861cbae676f