Malicious PDF — malware analysis report

Static analysis result for SHA-256 81dab4baa72745bd…

MALICIOUS

PDF

42.6 KB Created: 2020-07-09 17:16:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-08-25
MD5: 9ee9c3da53e4113b08c5962efddd51cc SHA-1: ade3d46513bf33117c53e63694ccce19a2d10b53 SHA-256: 81dab4baa72745bd9c8421a3e4bf17a59f2b25c0bd4bd3c30ff925edbf18d4a4
184 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to external PDF files hosted on various domains, suggesting a link farm or SEO poisoning attempt. One of the primary URLs, 'https://ttraff.ru/wb?keyword=perbedaan%20statistika%20parametrik%20dan%20non%20parametrik%20pdf', is flagged as a known malicious redirector. The ML classifier also strongly indicated maliciousness. While no scripts were extracted, the structure and URL analysis point towards a malicious intent to redirect users to potentially harmful 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.ru/wb?keyword=perbedaan%20statistika%20parametrik%20dan%20non%20parametrik%20pdf In PDF document text
    • http://files.finksdeli.org/uploads/1/3/2/7/132741222/5b0259.pdfIn PDF document text
    • http://files.maddiecranston.com/uploads/1/3/2/8/132815118/9015901.pdfIn PDF document text
    • http://files.inrarefiedair.com/uploads/1/3/1/4/131407629/b063a1956fd.pdfIn PDF document text
    • http://files.ict-conferance.org/uploads/1/3/1/3/131379049/2300739.pdfIn PDF document text
    • http://files.thepoetrypeople.co.nz/uploads/1/3/1/8/131856293/c4b2d6a90457352.pdfIn PDF document text
    • http://files.dictionaerie.com/uploads/1/3/1/4/131452991/wikuvuzeg_palezumudoxuna_fasobivul.pdfIn PDF document text
    • http://files.energysmartacademy.com/uploads/1/3/0/7/130739174/d6844.pdfIn PDF document text
    • http://files.sbtravelbureau.com/uploads/1/3/1/8/131871677/silamotidi_zawezusokurudo_saregit.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://kolodepigom.files.wordpress.com/2020/07/fixixoxer.pdfIn PDF document text
    • https://zetirufim.files.wordpress.com/2020/06/tanojapinujigaviz.pdfIn PDF document text
    • https://budixifanedo.files.wordpress.com/2020/06/14944949817.pdfIn PDF document text
    • https://tovuwaxupu.files.wordpress.com/2020/07/62560167824.pdfIn PDF document text
    • https://latavewudewe.files.wordpress.com/2020/07/83429465771.pdfIn PDF document text
    • https://zolibuvove523289473.files.wordpress.com/2020/06/9722650550.pdfIn PDF document text
    • https://zopowozofoje.files.wordpress.com/2020/06/nikuxuxof.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/fuwakuda.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/44603331863.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/54686169254.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/6565103434.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_off000068ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x68EE 5148 bytes
SHA-256: e052eaa7e29aa80409271651fd826635f572d59b6e2edd80b7ae246ada38971a
font_01_sfnt_off00007a46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7A46 10200 bytes
SHA-256: ca81f09d36bcab3227da0326b3c69e6a178cf31afcc42de780a9af8112170422