Malicious PDF — malware analysis report

Static analysis result for SHA-256 10928564f4ce2e69…

MALICIOUS

PDF

84.3 KB Created: 2021-07-03 00:09:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c61ce4911f282195794f31e14b608198 SHA-1: 0914df4f777f93548dc71646787cb336678a479f SHA-256: 10928564f4ce2e69af28f5f6566d1c5dfab9a3023be8cf96580bd771657ede33
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised websites, indicating a likely attempt to lure users to malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/3638af374fdc1e9f346efe1b35424431/munalipixunujowisuvufebe.pdf In PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160a754d072724---36343180486.pdfIn PDF document text
    • https://ringid.vn/ckfinder/userfiles/files/80372385666.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/mrmhipg3fmqdr6tv6gslfobmaa/8394033173.pdfIn PDF document text
    • http://ikkosushi.com/uploads/files/jelapoda.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/12278203366.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16072710da71a1---lixokagozisubimexekamesoj.pdfIn PDF document text
    • https://coevent.ru/upload/files/28173625097.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/15a5abd27f2c865d4129434c5900ed89/gilideranera.pdfIn PDF document text
    • http://congtrinhnhaviet.vn/upload/files/kawufetokop.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2816f49fd1---30981557086.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/87666a3242511623b64639e058d47f8e/sujuwepapixikakuv.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aac3b86d13b---75940212170.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d162c75b84---89064323042.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/wetikenubala.pdfIn PDF document text
    • http://muacuoi.vn/Pictures/files/9197002430.pdfIn PDF document text
    • http://seednseed.com/admin/fckfiles/file/90933899812.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/88011671821.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/18a9a53484b36bf697f01134c86ca3af/12085807029.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2af94e096---20185060704.pdfIn PDF document text
    • https://plasy.com/uploads/file/ligivamezijusamuko.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160783b0d34570---3907919122.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=density+calculations+worksheet+1+answersPDF 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_off0000e7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A1 16712 bytes
SHA-256: 9048e1154e701a119390bf8fe702f9516fe7f29702cc5af5400d832f982ca661
font_01_sfnt_off00011320.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11320 10772 bytes
SHA-256: e4df1b8bf8dbd149ea14a5282819723bf24539d72cbb236e929033fa87ee421d
font_02_sfnt_off00012c13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1