Malicious PDF — malware analysis report

Static analysis result for SHA-256 b673f3750c603ebc…

MALICIOUS

PDF

40.5 KB Created: 2020-08-10 07:29:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c60f78c79a6eac1099260caedde8e222 SHA-1: e252cf1676e344f2d6ebaca05885c1598a5f2f99 SHA-256: b673f3750c603ebc5bcca304927be6ece34a43557e6887e088b83101c0c19a99
152 Risk Score

Malware Insights

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

The PDF contains a significant number of embedded links, with a critical heuristic firing for a PDF link farm. One of the primary links directs to a known malicious redirector. The document body is heavily obfuscated and appears to be largely junk data, but contains the keyword 'kindergarten activities worksheets pdf' and a URL that matches the malicious redirector. The presence of numerous external PDF links suggests an attempt to manipulate search engine results or distribute further malicious content.

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.cc/pify?keyword=kindergarten+activities+worksheets+pdf
    • http://boluja.besureisofficial.com/uploads/1/3/1/3/131378776/fb1932f3e7.pdf
    • http://files.lizzdunich.com/uploads/1/3/1/4/131406049/5342307.pdf
    • http://files.goodworks.org.uk/uploads/1/3/1/4/131437775/6222700.pdf
    • https://cdn.shopify.com/s/files/1/0430/9457/3205/files/agency_coupled_with_an_interest.pdf
    • https://cdn.shopify.com/s/files/1/0431/6954/6395/files/8740788639.pdf
    • https://cdn.shopify.com/s/files/1/0429/1415/2607/files/rovoduguduwa.pdf
    • https://cdn.shopify.com/s/files/1/0435/9893/8274/files/5985859197.pdf
    • https://cdn.shopify.com/s/files/1/0431/5129/4619/files/kingdom_animalia_phylums.pdf
    • https://cdn.shopify.com/s/files/1/0440/7279/6325/files/lafivudizukew.pdf
    • https://cdn.shopify.com/s/files/1/0431/7341/3032/files/cg_police_si_notification_2020.pdf
    • https://cdn.shopify.com/s/files/1/0436/0926/0190/files/zujawakel.pdf
    • https://cdn.shopify.com/s/files/1/0435/1921/3727/files/97823513692.pdf
    • https://cdn.shopify.com/s/files/1/0432/3124/8541/files/jivuxuralavubazutub.pdf
    • https://cdn.shopify.com/s/files/1/0432/9380/2646/files/19451621370.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_off00005f09.bin
f7bf5b63198af9d572e2ff7188b2e7ce995df2dcf59071631d035028da2425bd
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F09 5572 bytes
font_01_sfnt_off0000721a.bin
011094d8fd4aa28b0466eb5625597aa3b2b93cf2d74ef9b3a3902e26870e1273
pdf-font-stream PDF embedded font (sfnt) at offset 0x721A 10348 bytes