Malicious PDF — malware analysis report

Static analysis result for SHA-256 51cc4b404e93295e…

MALICIOUS

PDF

52.1 KB Created: 2020-11-07 23:55:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-07
MD5: dce67fd60f9853a22653e7ff9b0ea07e SHA-1: 8fbdb1df5282f5509b6a8824c5a9bb7aa1321ba2 SHA-256: 51cc4b404e93295e3329f8c468ce31f30e5175620a10ed8431d66ba255663475
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to other PDF files, suggesting a link farm or SEO manipulation tactic. One of the embedded URLs, 'https://traffnew.ru/aws?keyword=theme+worksheet+4+answer', is directly presented in the document body and is likely the primary lure. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external links supports a malicious intent, potentially to redirect users to malicious sites or to distribute further malware.

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 https://traffnew.ru/aws?keyword=theme+worksheet+4+answer PDF link annotation
    • https://gibitiwatu.weebly.com/uploads/1/3/0/7/130776060/gafadox.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366367/normal_5f99d58043eef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383304/normal_5f9a211e94ee3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369900/normal_5f882f0311222.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378608/normal_5f905782b5efc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408702/normal_5f9ae4080fe95.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369646/normal_5f91f0f36325d.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/pazifetanegapu/analytical_chemistry_notes_for_bsc.pdfIn PDF document text
    • https://s3.amazonaws.com/paxivogedewilu/sozupobutar.pdfIn PDF document text
    • https://s3.amazonaws.com/jezaxojipevu/49890666655.pdfIn PDF document text
    • https://lefawos.files.wordpress.com/2020/11/52931902465.pdfIn PDF document text
    • https://s3.amazonaws.com/lumixi/virgin_pulse_max_buzz_instruction_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/fekazudabo/zonugaxeba.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00008fef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8FEF 5088 bytes
SHA-256: e48b3b6bffbed780a98e602b2fb90a13f95387be66a32168eaa4d634399c5a1d
font_01_sfnt_off0000a122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA122 10172 bytes
SHA-256: dbc0881dfc4733c80ccfae5a68c5cf4d6fcf5a425f627676e254794614674f9f