Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ec7f3da725e2de6…

MALICIOUS

PDF

89.8 KB Created: 2021-10-07 11:49:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 625b6d3664be2abf9871f79a2ddc2beb SHA-1: d76d62d8f3032b6d3bd2c332ed20c9e4662f044c SHA-256: 7ec7f3da725e2de6e914fa95e3af3a65dd5f7225d335b789ca8da4e374f63909
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains a link farm pointing to numerous external PDF files hosted on various domains, many of which are likely compromised or disposable. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a pattern of using such documents for SEO manipulation or to host malicious content. While no scripts were explicitly extracted, the nature of the link farm suggests an intent to redirect users to potentially malicious sites, possibly for phishing or malware delivery.

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://transilvaniafishing.ro/app/webroot/files/userfiles/files/meworedevusulojiledeni.pdf
    • https://episcopiaoradiei.ro/files/49039069489.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/36179744868.pdf
    • http://t-eamplus.de/web/editor/files/zasegekasazor.pdf
    • https://marikakozmetika.hu/editor_up/saxajopupixogeb.pdf
    • http://good163.cn/Uploadfiles/files/42657330064.pdf
    • https://centrorevisionimonregalese.it/file/4030863012.pdf
    • http://seattledesis.com/fckeditor/file/11808843563.pdf
    • http://benthanhsgfarm.com/images/uploads/files/3562499161.pdf
    • https://gmnavarra.es/ckeditor/files/30913300579.pdf
    • http://regmac.net/userfiles/files/50972373201.pdf
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/ae34c84bd56e95268a88284678135a77/83228362392.pdf
    • https://die-elke.de/cms/elke_page_files/file/46666836255.pdf
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/45cdd9e9d69ff6e903cc4507680cbb7f/57356572067.pdf
    • https://lawrenceyezersky.com/userfiles/file/17360423759.pdf
    • http://bielwod.com/userfiles/file/97588164137.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1615276bc11f7a---bonanemorofexesexigikev.pdf
    • http://www.pilatesyoga.hr/files/files/jariromavor.pdf
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16144f485a898d---resewusakifudifovej.pdf
    • https://ddmmaze.altruistictech.org/documents/img/upload/files/41590151369.pdf
    • http://www.trisad.kz/ckfinder/userfiles/files/82515855471.pdf
    • http://batterseataxi.com/survey/userfiles/files/82219285374.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=two+views+of+constructivism
    • 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_off0000f7a1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A1 16792 bytes
font_01_sfnt_off00010fb8.bin
c308d58daa1923d79b8a64e0bca09b9473caf66a6f919f0fb10bb3723363b3df
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB8 10504 bytes
font_02_sfnt_off000127be.bin
0f0d66f2704843d9756c49737d4335121cf3acda98e409ab82660560ebcd90e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x127BE 19496 bytes