Malicious PDF — malware analysis report

Static analysis result for SHA-256 03ac2fbef5796720…

MALICIOUS

PDF

41.6 KB Created: 2020-08-18 14:02:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c7148407c242b08b20dd324832f284ec SHA-1: b2f95150df71c9900c889c93b74784f2bb56a25c SHA-256: 03ac2fbef5796720b931793610a3df7036f7e0fdacc2ccd70fb1e7d5ad16befc
154 Risk Score

Malware Insights

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

The PDF contains a heuristic firing for linking to known malicious redirector infrastructure, specifically a URL designed to look like a 'Brainly unlimited answers' link. The document body, though heavily obfuscated, contains the same URL and a list of other PDF links, suggesting a link farm or redirection attempt. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the primary attack vector appears to be social engineering via a deceptive link.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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/pify?keyword=brainly+unlimited+answers
    • http://files.changemanagementassociates.com/uploads/1/3/1/3/131379894/kasewabu.pdf
    • http://files.vegetarianbutcher.org/uploads/1/3/1/1/131164081/ff15420a.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0430/6980/0597/files/jonejefotavopomojek.pdf
    • https://cdn.shopify.com/s/files/1/0429/5265/5002/files/xisumorozogabazom.pdf
    • https://cdn.shopify.com/s/files/1/0429/3427/2163/files/fapufuxijul.pdf
    • https://cdn.shopify.com/s/files/1/0433/3453/3275/files/descargar_diccionario_psicologico.pdf
    • https://cdn.shopify.com/s/files/1/0437/4704/9621/files/persona_3_portable_guide.pdf
    • https://cdn.shopify.com/s/files/1/0432/0627/9332/files/crash_course_economics_episode_13_answers.pdf
    • https://cdn.shopify.com/s/files/1/0430/1144/0803/files/galovemomujubimofofaguki.pdf
    • https://cdn.shopify.com/s/files/1/0440/5536/3734/files/58528958728.pdf
    • https://cdn.shopify.com/s/files/1/0436/1378/2173/files/gejamiroguba.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005ada.bin
da6c859ec5e2936bbe19fa1316b8e17b7c35291c1fd8d0b88014e8ff60da2ac7
pdf-font-stream PDF embedded font (sfnt) at offset 0x5ADA 5216 bytes
font_01_sfnt_off00006c89.bin
f5a3e0886b95c9b467f99b5e94d28133f575fbf2270330b68ad91cfe8bde1cf1
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C89 1884 bytes
font_02_sfnt_off000075a7.bin
7623df972e80c6b3008b1dfb06de585b2f0e64e6c05de64274af69cc03dd73bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x75A7 10572 bytes