Malicious PDF — malware analysis report

Static analysis result for SHA-256 c644e8fdcb8a3548…

MALICIOUS

PDF

73.0 KB Created: 2021-09-13 21:02:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6283c15177c66f975d22e322fc2acd16 SHA-1: 61442957c748067ab8c7ec50ffd67bf61db20ec6 SHA-256: c644e8fdcb8a35488f826aeb6141140acc7cf8fdc3bdb029916c93dfb6c75ac5
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate the file functions as a link farm, directing users to various external URLs, some hosted on compromised CMS uploads. The presence of multiple PDF link farm indicators suggests an attempt to obscure the true destination or distribute malicious content across various domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://energywork.pl/userfiles/file/23543450390.pdf In PDF document text
    • https://foursservices.com/nbloom/fckuploads/file/80416843764.pdfIn PDF document text
    • http://business-plan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/boludikuporenoxig.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/243d7dd0bb67beddc2e1816feb3dd4bb/najuvadokuzokoravireji.pdfIn PDF document text
    • http://tatnhapkhau.com/ckfinder/userfiles/files/24328046983.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ef5c64e75---kifibesakigitide.pdfIn PDF document text
    • https://bompentax.com/quangbasanpham/app/webroot/upload/image/files/86236837772.pdfIn PDF document text
    • http://jamalcar.com/userfiles/file/mujeteveju.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613556fb411be---zexut.pdfIn PDF document text
    • https://sindicav.com.br/ckeditor/ckfinder/userfiles/files/75000033782.pdfIn PDF document text
    • https://ixiu-23.com/uploads/files/202109050233216324.pdfIn PDF document text
    • http://saraswatishikshamandir.com/singhania/downloads/file/senomuperafikijenitozuna.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/vikef.pdfIn PDF document text
    • http://wienbildarchiv.com/upload_files/files/97099783710.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/rivunutulabonitunotari.pdfIn PDF document text
    • http://aquitaine.annuaire-regional.com/ckfinder/userfiles/files/5596743225.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c1398c318---gotekamegizubivom.pdfIn PDF document text
    • http://epoptavky.com/is/images/FCKeditor/File/7740580948.pdfIn PDF document text
    • http://montpellier-business-plan.eu/mbp/upload/images/images/upload/ckfinder/81150325521.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328e5e28f70---39672605317.pdfIn PDF document text
    • http://gotween.com/userfiles/file///2559554275.pdfIn PDF document text
    • http://kleinschaden.expert/userfiles/file/59452226264.pdfIn PDF document text
    • http://373113.linker.tw/files/kakovuratuxusadalelajam.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613675df12732---99161802749.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=devil+mod+apk+mlPDF 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://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/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_off0000bcfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCFB 16552 bytes
SHA-256: 296513051cd92c2b99ecad4e4c40234826c07bd4fa87c099d4ef48b8c5c92798
font_01_sfnt_off0000e7a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ffb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB9 10240 bytes
SHA-256: 309d3cba13bda410e78b73df78f1ba10344b9ff2b1ed54ab9f4028536a60dd1c