Malicious PDF — malware analysis report

Static analysis result for SHA-256 581e6980394a003e…

MALICIOUS

PDF

79.8 KB Created: 2021-09-05 14:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 72357b7e53c07d6a5c55c91d0723afe0 SHA-1: 2f432d5aeece45d89d81889cbcc69481f97425c3 SHA-256: 581e6980394a003e44ad9b10ac95be768a38c21140dd1fb5478335fb60da5499
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the PDF's structure suggests it's designed to act as a link farm. While no scripts were extracted, the presence of numerous links to potentially malicious or compromised sites indicates an intent to redirect users, likely for phishing or to serve further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/bf89865e65e1360a6ed9cddfcc48de3a/4531927250.pdf In PDF document text
    • https://nhahangphongcanh.com/uploads/files/17539195919.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca316b1450---72115557169.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/xafanik.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/b57a1ed3cae51006aa59101c9963406a/4854836942.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a18db2cf96d---galuwozaxosomenobux.pdfIn PDF document text
    • https://mimpiindahsatu.com/contents//files/daxadinafej.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/zidamewir.pdfIn PDF document text
    • http://danchrisjewelry.com/userfiles/file/14011097640.pdfIn PDF document text
    • http://victoryelectricalsupply.com/ckfinder/userfiles/files/11482925993.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/92900530919.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/79587544989.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/busukedukukowigupuliwafol.pdfIn PDF document text
    • http://inercial.es/uploads/files/kufazafofelu.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/70701553729.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/jufajelakesejaxibibiba.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-5/file/94260042450.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/59791810409.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bdeb19d05f2---33750286694.pdfIn PDF document text
    • http://meteosputnik.ru/userfiles/file/29957552792.pdfIn PDF document text
    • http://vinmexindia.com/uploads/23337373980.pdfIn PDF document text
    • https://dichvumoinoi.com/ckfinder/userfiles/files/47460720328.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100d9dbd0b7b---nizajokato.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=subtracting+mixed+number+fractions+worksheetsPDF 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_off0000d441.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD441 11472 bytes
SHA-256: 26944a5d9a0c23467c03bb34cca7b5e584067c1cc43f927718a99048d217dc40
font_01_sfnt_off0000ef16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF16 16464 bytes
SHA-256: 2908a885f19832e76400a56e52cbb3ba5b9a8f92338c0d2c64668dc4a588bd20
font_02_sfnt_off0001198e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1