Malicious PDF — malware analysis report

Static analysis result for SHA-256 54e9538916e31869…

MALICIOUS

PDF

36.4 KB Created: 2020-06-07 07:49:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: bb5c27e047e860a855f3b30d59696553 SHA-1: dc79da74fba1c092f9963a35175560762429eca3 SHA-256: 54e9538916e31869b86e3f810a98b7b161e9487c7f3ecebebda04ca0445f9f15
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1598.003 URL/Domain Link

The PDF file contains a large number of external links, a technique often used for SEO spam or to redirect users to malicious sites. The heuristic PDF_SEO_LINK_FARM specifically flags this behavior, indicating a potential link farm. The ML classifier also strongly suggests maliciousness. The document body, though partially corrupted, contains text related to 'Distribuição eletronica em camadas exercicios 9 ano' and mentions 'wkhtmltopdf', suggesting a lure document.

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://ricepaperstraw.org/uploads/1/3/0/6/130620546/130620546.html#distribui%25C3%25A7%25C3%25A3o+eletronica+em+camadas+exercicios+9+ano PDF link annotation
    • http://ademkracht.nu/uploads/1/3/0/6/130639368/xajesos-fekadujok-valaxibep.pdfIn PDF document text
    • http://74-123-77-189.mgwnet.com/uploads/1/3/1/3/131383453/2f6bf9d960b3f8.pdfIn PDF document text
    • http://immobiliaremyriam.it/uploads/1/3/0/8/130874389/125892.pdfIn PDF document text
    • http://customcateringco.com/uploads/1/3/0/4/130435905/vetejazibirilu.pdfIn PDF document text
    • http://nprycetest.com/uploads/1/3/1/4/131409508/1656205.pdfIn PDF document text
    • http://salemll.info/uploads/1/3/0/7/130738555/2441043.pdfIn PDF document text
    • http://hbcommunitymortgage.com/uploads/1/3/0/6/130605048/5943015.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://motajixug.files.wordpress.com/2020/06/jidarubita.pdfIn PDF document text
    • https://jijexore.files.wordpress.com/2020/06/61708571627.pdfIn PDF document text
    • https://nufaxubo.files.wordpress.com/2020/06/vexuto.pdfIn PDF document text
    • https://zonivip.files.wordpress.com/2020/06/57696775056.pdfIn PDF document text
    • https://nisedaki.files.wordpress.com/2020/06/godidakozajezuroxifukumer.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_off00005ebb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5EBB 12896 bytes
SHA-256: 5f584ede2c82c469e073d356886833d5cf4fef611123c63d020e3eb65ab34744