Malicious PDF — malware analysis report

Static analysis result for SHA-256 323768721ba0a9b0…

MALICIOUS

PDF

104.9 KB Created: 2021-08-26 19:34:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6a037f1fe356f14571a6ce5d4514ca16 SHA-1: 9306498aa3fbdd2a7ab1a2111877dba742c68acd SHA-256: 323768721ba0a9b030aa733e3cf317925651ca1711261b1a33c3801071cc305f
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of link farms and external URIs. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather to facilitate the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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 https://hogozaty.com/ckfinder/userfiles/files/kesuvidizuduzi.pdf In PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/160ac743f8b9e8---98545080581.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/29780338782.pdfIn PDF document text
    • http://weiken-rc.com/upload/files/xiran.pdfIn PDF document text
    • https://vicotelecom.vn/static/source/images/file/towemakepevojolareta.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608e1012817d1---pipegosagatulavag.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6274c4b402---79097059576.pdfIn PDF document text
    • http://rm-centr.ru/uploads/file/xuvolatudalituxazomowipi.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160922291cce85---3186642582.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name//files/jalugegufetujudukomen.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/divaxuzoji.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609b36b9e920b---86053137921.pdfIn PDF document text
    • http://olguanaokulu.com/upload/file/zapud.pdfIn PDF document text
    • https://anfauglir.com/images/file/69814945776.pdfIn PDF document text
    • http://www.wiz-fac.com/uploadImg/file/24787228179.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070474165145---97752416992.pdfIn PDF document text
    • http://mathcountsoutreach.org/userfiles/file/38172363007.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/7042900acebf952b1e9e3f176e97dbde/79382654406.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1609df2d863b88---45498002311.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/2205614030.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a6ffaadd92---xutokijevavidilojo.pdfIn PDF document text
    • http://dailyliving.nl/ckfinder/userfiles/files/gusolikoneduvawizadakelep.pdfIn PDF document text
    • http://sartor.ru/upload/files/6875662346.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16281434392105.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=richest+celebrity+in+the+world+2019PDF 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_off0001338d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1338D 11152 bytes
SHA-256: 3dca4e6ce684a0b77628aef8eaf78930c56b791d020c31b71db70463cbad7c8d
font_01_sfnt_off00014da6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DA6 18468 bytes
SHA-256: e3b61143e059c60690f0f3e3b975ea59110ae2d7e52fc618689f7e3b7a909b85
font_02_sfnt_off00017d74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17D74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1