Malicious PDF — malware analysis report

Static analysis result for SHA-256 f22fbf4e38983b33…

MALICIOUS

PDF

44.0 KB Created: 2020-04-06 09:38:28 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-07
MD5: 0522b325df37a11cec3aaed6a02ca6cc SHA-1: 377acd503b387b14965672ec08f9dcafe8a8770e SHA-256: f22fbf4e38983b33a3913cbac5553eb50e98911cb2fbf0866720765ac49d1213
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links pointing to various domains, identified by the PDF_SEO_LINK_FARM heuristic. The ML classifier also flagged this PDF as malicious with high confidence. The document body, though partially corrupted, contains a URL that is part of this link farm. The primary purpose appears to be directing users to a network of linked PDF documents, likely for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://mainelectricalsolutions.ca/uploads/1/3/1/4/131454466/131454466.html#literatura+en+el+renacimiento+en+espa%C3%B1a PDF link annotation
    • http://mtmusicservices.com/uploads/1/3/1/3/131398606/2851d9.pdfIn PDF document text
    • http://312thlegion.com/uploads/1/3/0/7/130776672/dbeb32.pdfIn PDF document text
    • http://romelocaltourguide.com/uploads/1/3/0/6/130604140/cb39775b.pdfIn PDF document text
    • http://bubbawubba.com/uploads/1/3/0/4/130483959/zelobipi.pdfIn PDF document text
    • http://junafurniture.com/uploads/1/3/0/4/130483400/tokeronamigufo.pdfIn PDF document text
    • http://cnaconsultancy.com/uploads/1/3/0/7/130740173/goloz-seviri-rijitoriw-sikadijumuluve.pdfIn PDF document text
    • 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://www.adobe.com/).NotoIn PDF document text
    • http://www.google.com/get/noto/http://www.adobe.com/type/ThisIn PDF document text
    • http://scripts.sil.org/OFLNotoIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007297.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7297 9180 bytes
SHA-256: 40366d119ed5539c3921617a39aa2e3361110f6f434bded3420ae3037bd8d18b
font_01_sfnt_off00009393.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9393 4236 bytes
SHA-256: d5ed1c3e32e121bc7fdf4b7f64e9f52042883cdc8d0b4eb1f0c73bff7e2be32e