Malicious PDF — malware analysis report

Static analysis result for SHA-256 836cd1d3ab338386…

MALICIOUS

PDF

63.6 KB Created: 2021-06-28 11:52:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 77e336a230537e4eb1fb6d79cf63c14d SHA-1: 0d2b9a1083810e8e4f8f83af5e10f15eb1779c5b SHA-256: 836cd1d3ab338386e37ddae8b8f90d55df3439e6257e54fe927acd8c2ff504f6
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites. These links likely lead to phishing pages or further malware downloads, indicating a spearphishing attachment attack vector. The document body was unreadable, but the heuristics strongly suggest a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5661

Heuristics 5

  • 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
  • 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://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/fs24ekqvnel3s04o6fauvk2d36/nukokaduwupilugizuvuxuwa.pdf In PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/t5ukkdd93r0dj8u23n8b23b1n5/duvisozesafuzes.pdfIn PDF document text
    • http://flatadministration.com/uploades/fckeditorfile/32093170665.pdfIn PDF document text
    • https://blnk.eu/userfiles/files/bugadisupotetudotux.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cd1fdec0b4---jewipalodexepovefuxutugif.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b52160810---botawalepokenu.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/1il70efek1r2vjnsjt1f4mp12h/fobebowesakabumulotov.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160724f15d96a2---42039443860.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607065c510529---32224944948.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a288dfe6a77---22429450933.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae6603fd35---59681994969.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f9cba6bc48---79342147038.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7296286a8---gasevokigiroke.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d5e885913---tedizifenamek.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/4ce86047c1109d5478142ccb0b8263c6/26686630886.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8b0d5dba7---79437749042.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160783269bd39e---16934602856.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/5168c086915ae4852b953fa3f2eeef81/kurezokujakalutikolelugo.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/xitebopixizak.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/99752287935.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/ubore9bgs5nb6vch9cjl4ecjk4/denekirazuzonalibojiwuviw.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a651a5c817---41400893983.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=among+us+unlocked+all+skins+and+petsPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c2c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2C8 10932 bytes
SHA-256: da0ebea4ccb26b6c19774a0a74341fa9e2d410a91d8198e80743592d67827064
font_01_sfnt_off0000dbfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1