Malicious PDF — malware analysis report

Static analysis result for SHA-256 77f8ab2ba7c11773…

MALICIOUS

PDF

35.5 KB Created: 2020-10-14 06:20:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: c81787314a9e607b32cd2aedd6905041 SHA-1: eca540aeb0c0d49d1e72c984b5345dfbd66ddd98 SHA-256: 77f8ab2ba7c11773fe97ab94540675d3db12f053429c7fe52092946e6b40ba2d
192 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links pointing to various PDF files hosted on disposable domains, a technique often used for SEO poisoning or to distribute malicious content. One of the primary links directs to a known malicious redirector, indicating a clear intent to lead the user to harmful content. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://gettraff.ru/strik?keyword=irregular+past+participle+exercises+pdf In PDF document text
    • https://dimaxafazeza.weebly.com/uploads/1/3/1/4/131453031/2697538.pdfIn PDF document text
    • https://gimejexoxixaza.weebly.com/uploads/1/3/1/8/131872185/kirorafagosox.pdfIn PDF document text
    • https://fodezamu.weebly.com/uploads/1/3/1/4/131407453/wijigomofiweb_lotitosede_jukis_dirum.pdfIn PDF document text
    • https://dutitujazekap.weebly.com/uploads/1/3/0/8/130814390/zikarab.pdfIn PDF document text
    • https://dimaxafazeza.weebly.com/uploads/1/3/1/4/131453031/zakeme.pdfIn PDF document text
    • https://xojerajap.weebly.com/uploads/1/3/1/3/131384359/2122744.pdfIn PDF document text
    • https://vuxozajuje.weebly.com/uploads/1/3/1/3/131379873/9031774.pdfIn PDF document text
    • https://genigudepa.weebly.com/uploads/1/3/1/0/131070712/7304884.pdfIn PDF document text
    • https://vuxozajuje.weebly.com/uploads/1/3/1/3/131379873/xenemavurinap_jokepirewiteda_fijalezej_gemewije.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0501/3602/3205/files/sparknotes_east_of_eden_characters.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0482/1522/8570/files/words_ending_in_er_in_spanish.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0437/9269/5456/files/24061856516.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_off00004b21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4B21 5328 bytes
SHA-256: 20f91b75dcdde62fcbb9c1fcf5825c6bc2ce77ab6097b5e7d0d66f44ee28116b
font_01_sfnt_off00005d4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5D4F 10592 bytes
SHA-256: 38861e674b7bcbd8855dba5ad0a08549fdb28775fd664a8ae257cbc6bfc913a9