Malicious PDF — malware analysis report

Static analysis result for SHA-256 39de140dff95f7ea…

MALICIOUS

PDF

73.2 KB Created: 2021-09-22 12:28:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ffd11c215a254b78ba18208f26bef69f SHA-1: 85e3719223d7d84bca23e57a7a0f8e3e502f121f SHA-256: 39de140dff95f7ea76f7f9d5fef904027b1e7f766b5a7ecde7520c347873d6dd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites, likely for phishing or SEO manipulation. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://coretry.ru/uplcv?utm_term=garry%27s+mod+css+textures+workshop
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408c1fc4d51---juvokarireku.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/161304b392228a---xalusemulinizukilowo.pdf
    • http://www.coverseg.com/uploads/ckfinder/files/15140173208.pdf
    • https://al-wesam.com/userfiles/files/13069420703.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eca83e5863---69264520540.pdf
    • https://beautydiction.com/ckfinder/userfiles/files/torifetumurof.pdf
    • https://afgventuregroup.com/cfiles/file/16322940074.pdf
    • https://luminex.pl/upload/file/fopuzipifimerut.pdf
    • http://sbnjl.com/userfiles/files/44558998552.pdf
    • https://susta.vn/userfiles/file/8378584245.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612eefa559153---tezagizelububebive.pdf
    • http://jayeonrak.com/upfile_editor/2021/files/52954416867.pdf
    • http://kuwaited.com/cote_dor_import/admin/ckfinder/userfiles/files/38119664022.pdf
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/80f71f6423f18803ea3e073828d9b6c2/87811516107.pdf
    • http://kidzcastleschool.com/singhania/downloads/file/dekejuvubiganit.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/161470ffbede40---198586738.pdf
    • https://qigoodteam.com/uploads/files/202109022056251143.pdf
    • http://innova-perila.ru/upload/files/fesipasus.pdf
    • http://novena99.com/uploads/files/202109101825094526.pdf
    • http://hstairan.com/FCKeditor/editor/filemanager/connectors/php/userfiles/file/nuwef.pdf
    • http://sgyscom.com/upload_fck/file/2021-9-17/20210917091310643453.pdf
    • https://777mto.org/contents/files/83344746215.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_off0000b82d.bin
3b50942e327384c2a6989f8ead67ca090b7940653b12ce7fb9a880e3ea011799
pdf-font-stream PDF embedded font (sfnt) at offset 0xB82D 16984 bytes
font_01_sfnt_off0000e3e7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E7 16792 bytes
font_02_sfnt_off0000fbfe.bin
65854c082f8bbcfd747d2abc2fa8b15d0c5e5423868a01364eb9fc877b9d1ad5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBFE 11104 bytes