Malicious PDF — malware analysis report

Static analysis result for SHA-256 55838d4bba2efbf3…

MALICIOUS

PDF

36.8 KB Created: 2020-03-28 06:39:47 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: 9f6ff085a00f7029a7f5ad4b0d60d06a SHA-1: ce0779f6d19bc38e118a175c6d34479976fe0dea SHA-256: 55838d4bba2efbf3c0822abd266b7123cdbe9c7c3f11952387f4f65c714304b6
96 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic. The document body, though partially corrupted, contains text related to accounting and acquisition costs, suggesting a lure. The primary function appears to be directing users to a vast network of other PDF files hosted on various domains, likely for SEO spam or to distribute further malicious content. No scripts were extracted from this sample.

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://wandersa.com/uploads/1/3/0/6/130604244/130604244.html#costo+de+adquisicion+contabilidad PDF link annotation
    • http://investnn.com/uploads/1/3/0/4/130476684/454137.pdfIn PDF document text
    • http://italtradesrl.eu/uploads/1/3/0/6/130604341/d9b772f.pdfIn PDF document text
    • http://tablorasa.com/uploads/1/3/0/5/130588702/1758510.pdfIn PDF document text
    • http://lakeviewbike.club/uploads/1/3/0/2/130270836/d64367e5f1.pdfIn PDF document text
    • http://gportablebuildingmovers.com/uploads/1/3/0/9/130969470/vosawaxavas-zomogigav-tenun-tatinabawesikiw.pdfIn PDF document text
    • http://angel-leather.com/uploads/1/3/0/6/130621628/tavuso.pdfIn PDF document text
    • http://pdxdrygoods.com/uploads/1/3/0/3/130313376/faridejaravox.pdfIn PDF document text
    • http://remote.enterprise-group.co.uk/uploads/1/3/0/7/130776578/bekuwexaxojox.pdfIn PDF document text
    • http://ecodiamondclean.com/uploads/1/3/0/7/130738638/7377786.pdfIn PDF document text
    • http://rtcconsulting.net/uploads/1/3/0/5/130543837/gibukojuw.pdfIn PDF document text
    • http://demenagementcd.com/uploads/1/3/0/7/130740196/megejikadokile.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_off000065e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x65E1 8632 bytes
SHA-256: 6c433d1ff344107ba6f3ad84266c4165e9676ebdd0970a82538ce303fbb0af51