Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4aadb76109a93e0…

MALICIOUS

PDF

39.8 KB Created: 2020-08-16 23:25:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e8a8aceed9f2b7663e4ca3ea40f3afb5 SHA-1: 5d50e1a59571c83d0d90bc884b8b6ce7cd67f70e SHA-256: e4aadb76109a93e01dfca45557c99a18caf98ddd836e13189314bc5d0220a36c
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link that redirects to a malicious URL, masquerading as an Avast offline update. This is supported by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic and the embedded URL. The PDF_SEO_LINK_FARM heuristic indicates a large number of outbound links, many hosted on Shopify, suggesting a tactic to distribute malicious content. The ML classifier strongly flagged this PDF as malicious.

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.com/pify?keyword=avast++offline+update
    • http://bemonomoz.jbhealth.co.uk/uploads/1/3/2/6/132695351/8456457.pdf
    • http://files.chambleesoccer.com/uploads/1/3/1/3/131379054/5367903.pdf
    • http://fuwesa.c34u.org/uploads/1/3/1/3/131384635/kurawobalugemusi.pdf
    • https://cdn.shopify.com/s/files/1/0429/3551/7337/files/kesilepevutikitajawaje.pdf
    • https://cdn.shopify.com/s/files/1/0435/6639/9647/files/lovebak.pdf
    • https://cdn.shopify.com/s/files/1/0432/0657/4240/files/sogipadetedop.pdf
    • https://cdn.shopify.com/s/files/1/0435/3448/3605/files/buku_sejarah_dinasti_abbasiyah.pdf
    • https://cdn.shopify.com/s/files/1/0428/8725/0087/files/55562751230.pdf
    • https://cdn.shopify.com/s/files/1/0431/9684/2142/files/11686413758.pdf
    • https://cdn.shopify.com/s/files/1/0433/2732/4310/files/67429599319.pdf
    • https://cdn.shopify.com/s/files/1/0429/9423/7589/files/free_vin_report.pdf
    • https://cdn.shopify.com/s/files/1/0436/5592/1822/files/2017485091.pdf
    • https://cdn.shopify.com/s/files/1/0432/8092/4837/files/94506026723.pdf
    • https://cdn.shopify.com/s/files/1/0430/8588/9689/files/77112807972.pdf
    • https://cdn.shopify.com/s/files/1/0433/4492/0734/files/36925584754.pdf
    • https://cdn.shopify.com/s/files/1/0431/6495/8879/files/interview_questions_and_answers_for_banks.pdf
    • https://cdn.shopify.com/s/files/1/0431/0564/8807/files/elternbrgschaft_miete_vorlage.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005f2e.bin
53b06fc49365a4fdb1d10fa540075c0aaaf7bcdb9f0fa7a422f56ffdadf66607
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F2E 4988 bytes
font_01_sfnt_off0000703c.bin
9fb7522bec81fa05d6fcf81147bdc84bc6224a6c795fa969bc0ac091ebedbb05
pdf-font-stream PDF embedded font (sfnt) at offset 0x703C 10052 bytes