Malicious PDF — malware analysis report

Static analysis result for SHA-256 d91e4f0105d2d7d6…

MALICIOUS

PDF

83.9 KB Created: 2021-09-16 15:57:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 913b549f8dbc5ae21fc5a07e1315c545 SHA-1: e484aa8f86a848edc49be899c436d9958afc5fc8 SHA-256: d91e4f0105d2d7d676e3e666a5c507d1df72b9854ae167d7ae44c93ae04d5e36
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm pointing to various domains, some of which are hosted on compromised CMS platforms or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded URLs further supports the attack pattern of directing users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://chcial.ru/uplcv?utm_term=ibs+and+dizziness
    • http://onlytech-tunisie.com/userfiles/file/visitakiwuvuf.pdf
    • http://hydrem.ru/images/file/pigoju.pdf
    • https://dammesliepas.lv/ckfinder/userfiles/files/72977668103.pdf
    • https://demo.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/22964627306.pdf
    • http://heizler.hu/files/file/kotoxepume.pdf
    • http://ck-buhgalter.ru/userfiles/file/13678683420.pdf
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b45b82ee8c---peligarafusavo.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/q3snft1bmrc3r2ti5j8eck8lh7/47097939202.pdf
    • https://luxurybaths.marblobaths.ph/app/webroot/img/files/kisokumenadureju.pdf
    • https://sanagustin.cl/files/21554692958.pdf
    • http://garankuccu.com/upload/fckimagesfile/aeaf7f5a09cfcfaa7b317ea35e52f3ef.pdf
    • https://alcoquimicos.com/ckfinder/userfiles/files/kosovujawafaxarubido.pdf
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210908_122336.pdf
    • http://kaiyudachem.com/filespath/files/20210908025637.pdf
    • http://dhleisure.com/ckupload/files/rusewuba.pdf
    • http://gzlmjx.com/data/home/bxu2343160066/htdocs/uploadfile/files/libuxekutofaxulabul.pdf
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/jt82vt9e9ioqgsebbcd20845v5/wumagubazeruwipalodudavum.pdf
    • http://ogledalata.bg/uploads/pages/files/70237793365.pdf
    • http://pappteam.hu/userfiles/file/68440658555.pdf
    • http://paddockj.com/user_data/editor/ckfinder/core/connector/php/upload/files/28562074723.pdf
    • http://15881588.com/ckupload/files/23473733959.pdf
    • https://eminenceconstruction.ca/viking1/uploads/files/91519620027.pdf
    • http://slkuang.com/v15/Upload/file/20219761582559.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_off0000e6c2.bin
9ece99a0388b358988cdb78d152e9226fd0a77d73f026f16493de0f1d5bc78f3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C2 17524 bytes
font_01_sfnt_off00011430.bin
129e91c522206e076e09b51d54317191604ac566522a7c7ff48ca9ddccd9fde5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11430 10028 bytes
font_02_sfnt_off00012a97.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A97 16792 bytes