Malicious PDF — malware analysis report

Static analysis result for SHA-256 821aed5d52c50087…

MALICIOUS

PDF

82.6 KB Created: 2021-09-12 01:22:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: debe97f08b13c08a564507b57a0170ea SHA-1: b00f324e681abace364478ebda28d6f1e6c43e13 SHA-256: 821aed5d52c5008776e3c27b2609d0e6a1faa86265dbc9e81758d9ad283036a3
164 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to phishing sites or download further malware. The presence of a 'download button' lure further supports a deceptive user interaction.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pistant.ru/uplcv?utm_term=snell+clinical+anatomy+latest+edition+pdf
    • http://ambiance-cinema.fr/wp-content/plugins/super-forms/uploads/php/files/a4c169bdf144f6463962f99819447d7c/82844477867.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161307c1facd78---nudobo.pdf
    • http://ky-auto.com/uploadfile/files/53522382297.pdf
    • https://spyboarcams.com/files/57083896623.pdf
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/9a279378e113080fc682a987c7fc3976/xileb.pdf
    • http://cioccolatogallucci.it/userfiles/file/56483684142.pdf
    • https://soudurelausiere.ca/upload/editor/file/83199821586.pdf
    • http://szakkepzosiklos.hu/upload/file/suwesevurar.pdf
    • http://xn--3e0b556bhrbowi6undva.com/ckupload/files/83296680457.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131ab2925a43---depenivizasafuramaw.pdf
    • http://ngocphuocjsc.com/public/default/ckeditor/files/xovemikonevofozu.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eecb43d933---tijenimalagugegedobola.pdf
    • http://bluekeydigital.com/images/pic/file/95521803364.pdf
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/32287119116.pdf
    • https://harom.ro/files/file/92210516414.pdf
    • http://veewood.com/file_media/file_image/file/72812872654.pdf
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/vugevi.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/0e601i6qe655mbg4jl63kko210/33026522743.pdf
    • http://lecostationery.com/files/file/7939607732.pdf
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7064d2d12367ff0b1dc832276cd2b73d/20050074405.pdf
    • https://holyfamilyhospitals.com/ckfinder/userfiles/files/96320843439.pdf
    • http://dbexpertise.fr/catalogue_dynamique/file/povuwasogavo.pdf
    • http://chemonova.com/FCKeditor/file/rupodigav.pdf
    • http://kriosispl.com/cote_dor_import/admin/ckfinder/userfiles/files/vejol.pdf
    • https://openkomm.yussfone-crm.com/userfiles/file/46985816467.pdf
    • https://beldapin.com/calisma2/files/uploads/47854686518.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_off0000db51.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB51 16792 bytes
font_01_sfnt_off0000f368.bin
143cc468d46f074fbf7e0c9593b64292b0cb83ac8fd071632a14c12a4407afa4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF368 10868 bytes
font_02_sfnt_off00010c84.bin
d9e6331ba66a9e1a5080755ef28bce7a7f7228ccbffccd18745f325a8af247a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C84 18356 bytes