Malicious PDF — malware analysis report

Static analysis result for SHA-256 55fd01a9eae7584e…

MALICIOUS

PDF

86.4 KB Created: 2021-08-23 15:05:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8613d51af05d77e394472c7aff049bd2 SHA-1: 14901c09c26833726059c2ac994941bb88cf2cb6 SHA-256: 55fd01a9eae7584eabf58b8ef37ed86557d500cc95dcfaf4d0e6b038739cffb8
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure points to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • 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.
  • 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://medicentrumnz.eu/medicentrum/files/file/97441898748.pdf
    • https://kalyna.ua/sites/default/files/userfiles/file/fuwodasizixor.pdf
    • http://kino-cosmic.ru/sadm_files/xepibijetipewafow.pdf
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b5c55d646ca---26313801553.pdf
    • http://physocare.com/Images_upload/files/41109767587.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609dee27e1a83---29498879584.pdf
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/5d751c9f31be888b7ec06e399613b7ab/62135060450.pdf
    • http://waterreducer.cn/d/files/12529816326.pdf
    • http://xn----itbbfrdrdbd4bgy6gi.xn--p1ai/webroot/files/files/pumuvesu.pdf
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/3444b54191133a6c895ac5a6285d5760/79898571298.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16091c05399823---41267545927.pdf
    • https://dycmc.com/DATA/upload/files/202106241124106202.pdf
    • http://angelofthewinds.org/ckfinder/userfiles/files/runatunugututepanowu.pdf
    • http://www.gdchgs.com/admin/img/files/12116811882.pdf
    • http://poiskvod.ru/images/file/bugorobopijodixejozabopa.pdf
    • http://keigan-productions.com/clients/863431/File/bezuzatiliza.pdf
    • http://ziva-muzika.cz/files/file/63235119107.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/b7ae5438c1d94ebbed19ddbd38d37b12/32536263923.pdf
    • https://motiv8workout.com/up/files/talutodil.pdf
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/rvo0hsj7tr5e2h4sj0qntjukm6/69328670422.pdf
    • http://ashioke.com/images/library/File/30490119444.pdf
    • https://olivierdaulte.com/ckfinder/userfiles/files/17700747657.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0afc610586---babakivubisozinekonu.pdf
    • http://baugeraeteverleih.de/benutzerdateien/muwofumubolewikokufemasu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=how+to+make+peanut+butter+whipped+cream
    • 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_off0000edac.bin
d8e40dc83b3ebb51247be51fcb30e02f62bdb4543b94138a524ce4f45f88d145
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDAC 17136 bytes
font_01_sfnt_off00011a5e.bin
85c4599b6a7bcb5e7301fc71e7d91f501fd03d0553bb1e65fef581edc9cb9c99
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A5E 10972 bytes
font_02_sfnt_off0001335f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1335F 16792 bytes