Malicious PDF — malware analysis report

Static analysis result for SHA-256 b88ccf22ff24e3b9…

MALICIOUS

PDF

80.3 KB Created: 2021-09-09 02:34:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a53779bd41239f097a92f1fe53c2cbf8 SHA-1: 0a0e7622ea7fea2d99eb2d9e3f2b6e2b758ad3e3 SHA-256: b88ccf22ff24e3b96b52d29ee2b96a46a96ffbd9a24ee31d0d578745ca725143
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, many of which point to compromised CMS upload directories or disposable hosting. The heuristic 'ML_NYX_PDF_MALICIOUS' strongly indicates malicious intent, with a confidence score of 0.996774. The presence of a link farm and the nature of the embedded URLs suggest a lure to download potentially unwanted or malicious software, such as the 'androrat app download' referenced in one URL.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • 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://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/2kh7p96nvioqnm62s2c4sfigc7/nofuvezemozalor.pdf In PDF document text
    • https://wic-net.com/userfiles/file/rudukobotuwubitupu.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/3694729617.pdfIn PDF document text
    • https://rintrans.com/files/tevizoserevojumokobe.pdfIn PDF document text
    • http://123dvere.sk/files/file/27564163639.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/puremuxobesox.pdfIn PDF document text
    • http://slovbau.sk/test/userfiles/file/ronamovugunuvoge.pdfIn PDF document text
    • http://sevoir.hu/uploads/file/xizamokuzede.pdfIn PDF document text
    • http://ceramvetro.net/userfiles/file/10345456426.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109041837237630.pdfIn PDF document text
    • http://musiclivemarsala.com/userfiles/files/24012944235.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/lodejedubudafuvuzufek.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/77016332826.pdfIn PDF document text
    • https://pomacanthe-art.fr/imagebeforeafter/files/80192290510.pdfIn PDF document text
    • http://musicandyouapp.com/webupload/editorimg/files/wasuwawubose.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130609510f0e---41555241844.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613389d483fbd---1219090919.pdfIn PDF document text
    • http://escrima-rlp.de/userfiles/file/tawekowalaketonusuresuge.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/f5f371f570d4e5999a2c5bdcdc875fb2/navexeterilexafijake.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/95116255093.pdfIn PDF document text
    • http://katour.ru/admin/ckfinder/userfiles/files/9152351645.pdfIn PDF document text
    • http://kangshi-you.com/uploads/files/202109090636152287.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=androrat+app+downloadPDF 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_off0000d874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD874 10060 bytes
SHA-256: 0eb9ff3edb092ab0bdb60e73137332d9b737ced65dbc68829cce0ed5800e13c5
font_01_sfnt_off0000eef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF6 17748 bytes
SHA-256: d05542fb492c99b37b8aecd370a08fbe8d19134f3a6af4922370ef09aab94a11
font_02_sfnt_off00011c28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C28 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1