Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fa9b6a822a7e593…

MALICIOUS

PDF

88.9 KB Created: 2021-09-11 12:20:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e5b70ee134b55ecd49a7508793068c7e SHA-1: 67d61cba79fc74d7d313a13bcebe70424af57ba5 SHA-256: 4fa9b6a822a7e5936fe3abe8f47acdf89352f581cf6fe659b8f591b50ba1804f
104 Risk Score

Malware Insights

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

The PDF file exhibits characteristics of a link farm, with numerous embedded URLs pointing to other PDF documents hosted on various domains. Several heuristics indicate that these links are likely part of a compromised CMS upload or a disposable hosting setup, suggesting a malicious intent to distribute content or manipulate search engine results. The ML classifier also strongly flagged this PDF as malicious, supporting the assessment of a potentially harmful link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://barrospizzadb.com/uploads/files/22035511058.pdf In PDF document text
    • https://fitness-sport.it/userfiles/file/58544229341.pdfIn PDF document text
    • http://koreadramatour.com/FileData/ckfinder/files/20210904_C95800421691CFBF.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/c6ebf301f11c49a2a71928d4041a0f07/dunamujifozijemekubive.pdfIn PDF document text
    • https://franchise-vietnam.com/app/webroot/img/files/36307646029.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/tojawifezuxikulogaboduxe.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/nomuladilotoberodo.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/87005671534.pdfIn PDF document text
    • http://le383.com/uploads/files/sunezegulowuzoroxib.pdfIn PDF document text
    • https://www.milestonesmn.org/ckfinder/userfiles/files/jakaja.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/ripokewoduj.pdfIn PDF document text
    • https://sanipro.ma/app/webroot/uploaderfiles/9031032686.pdfIn PDF document text
    • http://cheniou.handysociality.com/upload/files/muwuvivi.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/657f32aa5db55e4c52a46b26120c0be4/garugiriwuvegibamul.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/serazo.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/20656344754.pdfIn PDF document text
    • http://bociany.sk/media/file/25683151790.pdfIn PDF document text
    • http://gojjang.com/uploads/files/93935301715.pdfIn PDF document text
    • http://olymp-kiev.com/temp/fckeditor/file/32221944188.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/6282031055.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/265b44b30d827aa6e29b2956c596eb1a/63340844779.pdfIn PDF document text
    • http://kesherisrael.com/uploadEditor/files/suxiwilotabox.pdfIn PDF document text
    • http://rcp-ranstadt.us/files/jogukabosipadinajokev.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=android+install+app+twicePDF 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_off0000f360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF360 19808 bytes
SHA-256: 79907de4d217a2dbb1ec95cfcddad8e052c3e12887f8039dbf03ef0fbdad4a5d
font_01_sfnt_off000125e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013dfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DFB 10576 bytes
SHA-256: 5a41bbb93333bdbbc5ad86ca12716ee02e9caa3c5716b391ba3dadb526400a6a