Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5835139e9cfd678…

MALICIOUS

PDF

80.2 KB Created: 2021-09-06 20:50:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d6f559a921f4b254bd08532fab193c5a SHA-1: be141112e8f1b7c60f02974311fd52cf82de3a13 SHA-256: b5835139e9cfd678d73d7a437c24db645069e9015572676c2301218dc3baaeb0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and a link farm heuristic indicates the primary goal is to direct users away from the document, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://eurosan.pl/user_images/file/8218019691.pdf
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607b81a916ca1---41550228335.pdf
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/jd54g21ivdmd8nvi0ev1025mkq/42194984498.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/013klci8u24gi9pvelhaglko63/30767609348.pdf
    • http://tate79.com/clients/868750/File/sepuzufuro.pdf
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/nofik.pdf
    • http://barudan.hk/UploadFile/file/20210610013217032.pdf
    • http://ceomit.com/fckupload/file/talowugewo.pdf
    • http://caydinhlang.net/userfiles/image/file/11970509558.pdf
    • https://groupburuemas1.com/contents//files/segug.pdf
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/8fa2b20bc95c673ba79ebb2bb3e65c5b/44574997418.pdf
    • https://dalycity.com/wysiwygfiles/file/66358607742.pdf
    • http://ainut.fi/userfiles/file/24828670187.pdf
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/92102444853.pdf
    • http://sungsam.net/userData/board/file/lubizobawumu.pdf
    • https://ville-saintleonard.fr/pdf/29596476518.pdf
    • https://ladymamashop.com/uploads/files/202108280318474992.pdf
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/11k89pf9bcv8h1qej1ok9hf4nv/dinejivalezativebexi.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160e44a4aee3d0---97395193624.pdf
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/jivabe.pdf
    • https://traveletrust.com/basefile/traveletrustcom/files/fegasar.pdf
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076243719f2a---88080166894.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/qhjcun5vu467qchrvco5l0o901/dafurumije.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=subject+verb+agreement+singular+plural+worksheet
    • 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_off0000d257.bin
30c9995bd153388b74e0ddf8efe70fc51df31226efa8cddf0b177d04b67cb8c9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD257 17792 bytes
font_01_sfnt_off00010085.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10085 16792 bytes
font_02_sfnt_off0001189c.bin
850c4e1508072aa80e6df8a370f5d77547236174f0394de62e766ed16c140a89
pdf-font-stream PDF embedded font (sfnt) at offset 0x1189C 11508 bytes