Malicious PDF — malware analysis report

Static analysis result for SHA-256 659a0759a60b0339…

MALICIOUS

PDF

37.3 KB Created: 2020-03-06 16:55:11 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: 21d169dbb787265ccd3b17cd0301b553 SHA-1: 21e6503632ba6826b4ad1a7cee02b16719202286 SHA-256: 659a0759a60b0339b01712ed8ec1fce6897f52bea8862c55c6ed440f6a7289bd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a large number of embedded external links, identified as a link farm. The primary URL http://yourchairmansclub.us/uploads/1/3/0/7/130776769/130776769.html#multinomial+logistic+regression+stata+change+reference+category appears to be part of this scheme. While no scripts were explicitly extracted, the heuristic 'PDF_SEO_LINK_FARM' suggests a malicious intent to manipulate search engine results or redirect users to potentially harmful content. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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://yourchairmansclub.us/uploads/1/3/0/7/130776769/130776769.html#multinomial+logistic+regression+stata+change+reference+category PDF link annotation
    • http://keithwardfiction.com/uploads/1/3/0/3/130379158/limebenovax.pdfIn PDF document text
    • http://reahomesllc.net/uploads/1/3/0/2/130271067/rozeni.pdfIn PDF document text
    • http://sciencemeetsfood.com/uploads/1/3/0/7/130776219/gurilevivonez.pdfIn PDF document text
    • http://bartbenson.com/uploads/1/3/0/7/130775259/dizos.pdfIn PDF document text
    • http://iquiver.net/uploads/1/3/0/5/130541743/depowadazamupolonoze.pdfIn PDF document text
    • http://www.saullelchuk.com/uploads/1/3/0/4/130476563/mowexogedapu.pdfIn PDF document text
    • http://multiskim-plastering.com/uploads/1/3/0/4/130435998/5698661.pdfIn PDF document text
    • http://helloinfinta.com/uploads/1/3/0/4/130476277/56ffd0b8a1.pdfIn PDF document text
    • http://feralcatbrewing.com/uploads/1/3/0/3/130323277/1880595.pdfIn PDF document text
    • http://rossanaporta.org/uploads/1/3/0/6/130604126/4028464.pdfIn PDF document text
    • http://www.athleterealtyadvisors.com/uploads/1/3/0/5/130550881/luzenise.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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000067d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x67D3 8208 bytes
SHA-256: d71952e379a0fa5cd54ed9be719062cda24007528a23b0ee702a504c56961aac