Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1e3d80a87bf3629…

MALICIOUS

PDF

34.6 KB Created: 2020-06-11 19:18:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-08-25
MD5: ac81ff87baac2cab1cc2ff2f68ce1997 SHA-1: e67ff4d721e7f569c7aea57571e6d49a9cf85b1c SHA-256: a1e3d80a87bf362932a431a9ff38dbc4866a729d61928c3682df951c0c2bb011
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various domains. The ML classifier also strongly indicated maliciousness. The primary attack pattern appears to be SEO poisoning, where the PDF acts as a lure to a network of other PDFs hosted on unrelated domains. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://coastalbarn.com/uploads/1/3/0/6/130605168/130605168.html#primavera+p6+print+to+pdf PDF link annotation
    • http://friendsofhaines.org/uploads/1/3/1/4/131438050/fogupitadozeduxe.pdfIn PDF document text
    • http://frukosthem.com/uploads/1/3/0/6/130639643/a7231ac5eb464c.pdfIn PDF document text
    • http://paramountplumbingservices.net/uploads/1/3/1/4/131453096/diweke.pdfIn PDF document text
    • http://hostmaster.darlingtonlecture.org.uk/uploads/1/3/1/8/131871579/nubudojuz.pdfIn PDF document text
    • http://churchweddingspaphos.com/uploads/1/3/0/8/130814169/7969040.pdfIn PDF document text
    • http://dirtbyearth.com/uploads/1/3/0/6/130605442/matexekisiko-fajepimeba-gebodelone-rujubew.pdfIn PDF document text
    • http://ubisoftsite.xyz/uploads/1/3/0/6/130604018/lelafomurunijofod.pdfIn PDF document text
    • http://ericfellow.com/uploads/1/3/0/4/130490019/dusepewubuzako-wamomowagap-wovumupabafezis.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bemosej.files.wordpress.com/2020/06/zezavaxab.pdfIn PDF document text
    • https://wegekivosum.files.wordpress.com/2020/06/guvubekavepew.pdfIn PDF document text
    • https://muwafinatub.files.wordpress.com/2020/06/63139198298.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005c83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5C83 10152 bytes
SHA-256: f498fa8c9cf36b7bdf5e0cce26d2acee29ad7d9b20f9007f33d94353db98a8df