Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc7eb5b1f8da8326…

MALICIOUS

PDF

41.1 KB Created: 2020-07-08 11:14:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-08-25
MD5: eaa3cf1150f93ebbca83793edd341d31 SHA-1: 0995591da5608bb5f0967813585cc5eba1277a98 SHA-256: dc7eb5b1f8da832632c42f7c1df51d60ffcea16f3bd7ca98c65dd123d9f599b2
184 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to external PDF files hosted on various domains. One critical heuristic identified a link to a known malicious redirector, and another flagged the document as a link farm, suggesting an SEO poisoning or phishing campaign. The ML classifier also strongly indicated maliciousness. The primary intent appears to be directing users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • 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://ttraff.cc/wb?keyword=preguntas%20indirectas%20en%20ingles%20ejercicios%20pdf In PDF document text
    • http://files.kocanada-usa.com/uploads/1/3/1/4/131437538/zorodoke.pdfIn PDF document text
    • http://files.commerciallockandsafe.com/uploads/1/3/0/9/130969242/206112.pdfIn PDF document text
    • http://files.myvirtualdietitian.com/uploads/1/3/1/0/131071035/pavevagalumoga.pdfIn PDF document text
    • http://files.all4pawsdogrescue.com.au/uploads/1/3/1/4/131455883/9425829.pdfIn PDF document text
    • http://files.chrischiropracticservices.com/uploads/1/3/1/4/131437753/2163686.pdfIn PDF document text
    • http://files.tinagutierrezartsphotography.com/uploads/1/3/0/7/130775383/remax-taxopugazaledu-fuluxibejurifuj-lavosiraleset.pdfIn PDF document text
    • http://files.chenowethbairddesign.com/uploads/1/3/1/8/131871894/kawal_fudomur.pdfIn PDF document text
    • http://files.blockchain2033.com/uploads/1/3/2/6/132682681/2695de3aa.pdfIn PDF document text
    • http://files.orangehistory.org/uploads/1/3/1/3/131380998/6a7d3c8e67aa6.pdfIn PDF document text
    • http://files.panoramiccave.com/uploads/1/3/1/3/131379325/1380becf78.pdfIn PDF document text
    • http://files.willowwildedges.com/uploads/1/3/1/8/131856443/xukopiwome-tojazelapiz-kasivezobisu-sunezurawuse.pdfIn PDF document text
    • http://files.workinnvision.com/uploads/1/3/1/3/131384018/zudemesenodevakani.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://kibazuson.files.wordpress.com/2020/07/21902985715.pdfIn PDF document text
    • https://fovuweba408505925.files.wordpress.com/2020/06/31976156964.pdfIn PDF document text
    • https://xenavako.files.wordpress.com/2020/07/95529171345.pdfIn PDF document text
    • https://savisos.files.wordpress.com/2020/07/47885531615.pdfIn PDF document text
    • https://tizatovizux184684867.files.wordpress.com/2020/06/ditaloguzimevetiboxetawa.pdfIn PDF document text
    • https://zejuguguma.files.wordpress.com/2020/06/gukibizozozumi.pdfIn PDF document text
    • https://voluvatoru.files.wordpress.com/2020/06/22388672745.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_off000060a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x60A6 5280 bytes
SHA-256: 15270f924e672363ca9dede2a9b0816f4a79f839fd6504a158031300cbe6578a
font_01_sfnt_off000072a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x72A4 11208 bytes
SHA-256: 8c73abce6aa7724df57154d920ac3270001dc2f77d0cf1ede419157d0d958692