Malicious PDF — malware analysis report

Static analysis result for SHA-256 21bef358f5a3c773…

MALICIOUS

PDF

85.4 KB Created: 2021-06-27 22:01:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c3fbf8e03497b26bc346bf2a4210aef8 SHA-1: d1126bb77e2861bad847c1746ff5c0446218b720 SHA-256: 21bef358f5a3c7738825c611338d2305c5b949a518aa3bd189907ec9bd01c11f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF was flagged by multiple heuristics as a link farm hosted on compromised CMS uploads, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is unreadable, but the presence of numerous links to potentially compromised WordPress sites suggests the primary goal is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160bd2f9c4a875---76602342570.pdf
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/40e23288782d0128aa6e9cfc9f6a2684/jutixamimugawanosurajiv.pdf
    • http://studiogiovannone.com/userfiles/files/gajam.pdf
    • http://wo-kop.pl/userfiles/file/midexurulofoj.pdf
    • http://gabortech.comadmin/file/mutudamarakisud.pdf
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c67d64f1d---35300153900.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/1b2a299853306eb236b46c926e53e84a/wefilexiwipesa.pdf
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a908cbf3273---91081399644.pdf
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/e0ca55f67a3b22ac7fd912fb14b05ff6/96346011388.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e9a47dece---44622964826.pdf
    • https://aplusadvance.com/naver_editor/data/file/mepitegujomopurukolegifan.pdf
    • http://niszczeniewaw.pl/userfiles/file/66028539699.pdf
    • http://bsinteriordesigner.com/userfiles/files/nobogizejuxexepo.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1609e00eadcbb6---degezov.pdf
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202105022232112812.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160afdb55122e1---regixakukomugalupa.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/2dej45fd06tsjrecpf7j50lqv0/66806695782.pdf
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609782019bcb3---90107146880.pdf
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160987d390860b---rinapapisigagukefebad.pdf
    • http://adria-ex.com/images/blog//file/daxoxunuve.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=dymo+labelmanager+300+user+manual
    • 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
stream_004_off00011acc.bin
248565b4b21b3c5129820379735123e58b235dc27921efda48e3e685c6884f75
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x11ACC 17496 bytes
font_00_sfnt_off0000e977.bin
0b4a9fb3e0012e7ebd165c5a63d3f77d9e49b1994faaa4c3e6e481adedf5e2b7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE977 10908 bytes
font_01_sfnt_off000102ba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102BA 16792 bytes