Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a21872cf7456e7f…

MALICIOUS

PDF

79.7 KB Created: 2021-09-07 01:05:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 91e96281cd391391586f07b4dd914b35 SHA-1: a552290cd84de287c598807ad5b639a40f30b01d SHA-256: 7a21872cf7456e7fe79838dc6923ae1c785f19fbea6fcc976389749fcb4ca5d7
154 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The PDF's structure and embedded links align with common phishing lures, likely intended to trick users into visiting these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6148

Heuristics 5

  • 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
  • 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=21+indispensable+qualities+of+a+leader+pdf PDF link annotation
    • http://nesemlak.com/test/images/uploads/files/jowigi.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160767a275438f---xadazisaxu.pdfIn PDF document text
    • http://bainihu.com/upfiles/editor/files/72125207950.pdfIn PDF document text
    • https://408of53crownstreet.com/assets/media/files/26395306343.pdfIn PDF document text
    • http://ferrocom-spb.ru/userfiles/files/69280429313.pdfIn PDF document text
    • https://smaransaving.com.np/ckfinder/userfiles/files/91746368184.pdfIn PDF document text
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/d9u6if8jhqeqrkj8i3gqecaf12/rusewagojigidew.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1ffc5b92cb---84368807391.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/60740113701.pdfIn PDF document text
    • https://getracemirates.com/userfiles/files/79566133018.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/17367338114.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/69c00dfcd07744f28bc8878ff754c91f/21918495777.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d612280a3f8---begusutuxawefagafilus.pdfIn PDF document text
    • https://munis-roquesalbes.cat/demo/vilalba/imatges/file/14313047839.pdfIn PDF document text
    • http://cesarrodarte.com/userfiles/file/vemaje.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfb39bf07d---turaletifat.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16130445269502---zaledoka.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160adc11919570---63781926612.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/2hf8ievsak2119ngpmovrarg40/xoxokob.pdfIn PDF document text
    • http://djarkitek.com/temp/vinney/HTML/userfiles/file/dofefetimuj.pdfIn PDF document text
    • http://moscow-vernisage.com/files/files/65151910769.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/7903b3231fd5f367d49f7addbee893b3/93985342058.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607db82338540---fetivugog.pdfIn PDF document text
    • http://hanabi-la.com/uploads/files/18728310320.pdfIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10817 17660 bytes
SHA-256: 5d6432b3d5f4a4618b8a6cb035d1dccb334e7a057bb08e8bf60aa372148b0e05