Malicious PDF — malware analysis report

Static analysis result for SHA-256 998cb668f9b87130…

MALICIOUS

PDF

179.5 KB Created: 2021-07-07 14:36:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b879d279aaf4c1406e47c75deb73da48 SHA-1: d2f076d1ad9226bc60f968a55789a9b633fa4ba4 SHA-256: 998cb668f9b87130cc6103b80bf02392a149872a7d98546d22037cee063e0838
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a large number of embedded URLs, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure indicate an attempt to distribute malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9742

Heuristics 6

  • 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.
  • 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://chcial.ru/uplcv?utm_term=thirtieth+of+march
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e2f088f31---dakekokazuvosubemomamebuz.pdf
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/e2201a0f5822ebd6ed99399436926730/sutafudijopin.pdf
    • http://pandoreunion.com/clients/81456/File/61319505012.pdf
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/zagogosavupomopuxejami.pdf
    • https://wita.lt/images/files/pijewibusenanar.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/e412ac8e8de272b84ed11c95845d4516/16690932793.pdf
    • http://hitecds.com/userfiles/file/fudevoxigam.pdf
    • http://ats-dz.com/userfiles/file/wolukodunuzeg.pdf
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/2d4b9d8a093ab6c5dfcf09b5f9446091/tokigesumoge.pdf
    • https://www.swissfillon.com/wp-content/plugins/super-forms/uploads/php/files/9ed0b2790ec193459d73501a1e0972d2/sudazituzimetiserasufam.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/tk8apldtu4lu6olci31ktp66a7/91337585496.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/16075c918012c6---tosebefef.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/s2snhsccj3oi24eseh8d5l2rls/20350451755.pdf
    • http://jamesirvinewedding.com/clients/f/f9/f947a18657f5d77a8fcd192ffd4ccf25/File/pijikonegezijolup.pdf
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/e2fd2398dadfb6f63bdd5e647276b1c8/nudononad.pdf
    • http://akinmedical.com/uploads/file/babuxababomanafenolidonox.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/206fe07b137ad49926a73a0a6cbcf4f1/gurapexibu.pdf
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16093a4d84dc8d---17157730950.pdf
    • http://nutranghongngoc.com/media/ftp/file/61732169303.pdf
    • http://alexandercdg.com/clients/36029/File/56525536472.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a26520af467---lapet.pdf
    • http://metafelix.it/userfiles/files/mitomokogur.pdf
    • http://kythuatviet.vn/uploads/userfiles/file/99357676389.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609eea5e46059---8334874877.pdf
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ee69757815---kojefanilegobusu.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e589c5e85ff---42651098353.pdf
    • 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_off00025d8c.bin
82f75e5730404f2147e3c5e080e9a3aa68e73ffd201cb86af5858e373a41cac8
pdf-font-stream PDF embedded font (sfnt) at offset 0x25D8C 10244 bytes
font_01_sfnt_off0002749a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x2749A 16792 bytes
font_02_sfnt_off00028cac.bin
8253cf5630bbf532c332c8fb17cc831a11a67c14db2f60deffc7bbb44f0032c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x28CAC 19680 bytes