Malicious PDF — malware analysis report

Static analysis result for SHA-256 23bef259c537e7ce…

MALICIOUS

PDF

80.2 KB Created: 2021-08-31 21:08:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3149efda1d27402ec7d2b3fe1697f93a SHA-1: 8a208ccbe508ff7864417868dbc853c49db50c98 SHA-256: 23bef259c537e7ceb44d49bf6339fc8be845436a36047136b02c7b1c811f4e12
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The embedded URLs, while numerous, do not appear to be directly executable, but their association with compromised sites and link farm tactics points towards a malicious distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 http://daoltrading.com/userData/board/file/wukoxekiw.pdf In PDF document text
    • http://olimpic.hu/ckfinder/userfiles/files/tewaxagajivef.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/43026063910.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/8098af45fb7c54a584b487cca730e806/fidovuwiges.pdfIn PDF document text
    • https://badeluxe.com/userfiles/files/99325566516.pdfIn PDF document text
    • http://mextro.de/upload/files/72526003402.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210817_075454.pdfIn PDF document text
    • http://tradeweb.es/userfiles/file/23820870216.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cecad1a2c6---fabirubatefizubofefaxar.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1610db1af664e3---jajerutuvolejamuxamaxa.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/xafofamonof.pdfIn PDF document text
    • https://hyosungulf.com/uploads/file/17246731800.pdfIn PDF document text
    • https://cvssteelex.com/ckfinder/userfiles/files/pikidomurifiwoga.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/fbdb469bedf86d48fa5a8a021dc89fea/pugituxemarak.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202108190324111878.pdfIn PDF document text
    • http://crescentcarpets.com/userfiles/file/xudumezi.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/33edcl2ek5vchk8sba4ukvc651/72468372310.pdfIn PDF document text
    • http://logistra.fr/ressource/site-image/files/43475069658.pdfIn PDF document text
    • https://familienarbeit3plus.ch/userfiles/files/58457009435.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/82b22bcd57a1891759afdd37170686a8/xufofexujimur.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160bb2cb668bc7---74336671575.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16084d453f396f---vafuzonasu.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/33265019732.pdfIn PDF document text
    • http://www.firengo.com/userfiles/files/xawegivejolugaduxelub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=convert+mp4+to+mp3+on+iphonePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA0B 10488 bytes
SHA-256: 70b0146ffbd2256ecc7aee002e7e9e6ea5d3cf01eebadc2c3853f1c461fe646b
font_01_sfnt_off0000f1be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1BE 17892 bytes
SHA-256: 5cab44197c10dba35874d4e383cb6b3e06b17da6ed06442b1b799c989cab7c12
font_02_sfnt_off00012051.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12051 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1