Malicious PDF — malware analysis report

Static analysis result for SHA-256 a87a6d7018a928c7…

MALICIOUS

PDF

34.3 KB Created: 2020-08-12 07:05:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1b295646fa9757a7ab9ef728a6cd40f9 SHA-1: bc91f13d3b7ce49a14ab43b6971e2a60235e395a SHA-256: a87a6d7018a928c729768f61cb80a884e0af306a8f19435b04d2104befc96d04
152 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links, many of which point to potentially malicious redirectors or link farms. The ML classifier strongly indicated maliciousness. The primary attack vector appears to be a link farm designed to redirect users to malicious content, leveraging the document's apparent theme of educational worksheets.

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=punctuating+dialogue+worksheet+pdf+with+answers
    • http://files.dyslexia-nsw.com.au/uploads/1/3/2/6/132683087/3610865.pdf
    • http://vuzokuk.friendshipcharitiesinc.org/uploads/1/3/1/8/131857419/xixeweruvagodis.pdf
    • http://tukuvat.lavedettebooking.com/uploads/1/3/2/7/132710797/660df9d82f346.pdf
    • https://cdn.shopify.com/s/files/1/0431/9592/4640/files/wondershareelement_6_professional_crack.pdf
    • https://cdn.shopify.com/s/files/1/0428/8161/3987/files/58682572800.pdf
    • https://cdn.shopify.com/s/files/1/0437/4138/0759/files/holt_mcdougal_larson_algebra_2_common_core_textbook.pdf
    • https://cdn.shopify.com/s/files/1/0433/0923/6374/files/gajul.pdf
    • https://cdn.shopify.com/s/files/1/0431/4333/2000/files/cisco_ccna_routing_and_switching_icnd1_pdf.pdf
    • https://cdn.shopify.com/s/files/1/0439/6823/3630/files/71716445440.pdf
    • https://cdn.shopify.com/s/files/1/0452/4628/3937/files/10th_maths_textbook_download.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/92283418618.pdf
    • https://cdn.shopify.com/s/files/1/0431/5742/2229/files/tolkien_letters.pdf
    • https://cdn.shopify.com/s/files/1/0428/5625/1555/files/pidopinogi.pdf
    • https://cdn.shopify.com/s/files/1/0434/4712/4130/files/1824414769.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_off000047f8.bin
cb9cdac1f3b47a68d1daedf76dab448cc76d35c695fb678e7a4ec51a749cc718
pdf-font-stream PDF embedded font (sfnt) at offset 0x47F8 5576 bytes
font_01_sfnt_off00005af0.bin
e269f555bfa6759bc3a6879254ff3eff6d2f111c4da823bd393f9912754fc2f7
pdf-font-stream PDF embedded font (sfnt) at offset 0x5AF0 9828 bytes