Malicious PDF — malware analysis report

Static analysis result for SHA-256 81748e464084e597…

MALICIOUS

PDF

39.4 KB Created: 2020-08-17 13:58:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f21a9b352de8772bdfa5e9b8f0fa6c3c SHA-1: da9cb0294690d3d5c6bab7db62bf8af1d9e2e910 SHA-256: 81748e464084e5976c4a0a489e6d0abc226d55152185e609e7d7497af36fb4e4
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious due to a high number of embedded links, many pointing to external PDF files hosted on various domains, suggesting a link farm or SEO manipulation tactic. One critical heuristic identified a link to known malicious redirector infrastructure. The document body contains the text 'Brainstorming worksheet esl' and the URL 'https://ttraff.ru/pify?keyword=brainstorming+worksheet+esl', indicating a potential lure for users searching for educational materials. No scripts were extracted from this sample.

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=brainstorming+worksheet+esl
    • http://files.fccwareham.org/uploads/1/3/2/7/132740860/4414195.pdf
    • http://rorinako.theragirl.com/uploads/1/3/2/3/132302780/sukagotisopojup_nozuwovarejini_wofituv_dodolofa.pdf
    • http://kiwuxem.missrodeokansas.org/uploads/1/3/1/4/131437436/6a3e37e9b79.pdf
    • http://files.eliteconstructioncharleston.com/uploads/1/3/1/4/131438891/b96a90162a7456e.pdf
    • https://cdn.shopify.com/s/files/1/0433/8837/1107/files/vituwilobubifefos.pdf
    • https://cdn.shopify.com/s/files/1/0430/5915/1009/files/detimone.pdf
    • https://cdn.shopify.com/s/files/1/0433/7542/7735/files/xuxoxi.pdf
    • https://cdn.shopify.com/s/files/1/0432/1935/3757/files/kolemobexakorukuje.pdf
    • https://cdn.shopify.com/s/files/1/0431/7937/6798/files/xikevikinukij.pdf
    • https://cdn.shopify.com/s/files/1/0429/9833/3599/files/zip_code_to_lat_long.pdf
    • https://cdn.shopify.com/s/files/1/0427/5778/3718/files/kisekanugijosuwefenosoxa.pdf
    • https://cdn.shopify.com/s/files/1/0439/3048/4904/files/nukosegodumi.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_off00005b86.bin
6aa710c0e64d74895b5c8772c711783bb9fc9fd286f94ddd1a6c0215712a4a83
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B86 5304 bytes
font_01_sfnt_off00006d73.bin
41681c7a2843baf758980d71aba22452fb80ebfbf9b1ca023afae023f3d7c4a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D73 10428 bytes