Malicious PDF — malware analysis report

Static analysis result for SHA-256 23e5139511cbc193…

MALICIOUS

PDF

41.1 KB Created: 2020-08-13 22:15:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1eae9a3e34b979583d6c874bd0f92745 SHA-1: 2a13a14f59023a3a9070d683004f0e96e3f45e97 SHA-256: 23e5139511cbc193780c4e9a843247c33ad367a9642bf518c6a48ba1a2c695d4
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to Shopify domains hosting PDF files, suggesting a link farm or SEO poisoning tactic. One critical heuristic identified a link to a known malicious redirector, ttraff.cc, which is used to obscure the final malicious destination. The document body, though heavily obfuscated, contains the string 'Greek and latin roots worksheets pdf' and the malicious redirector URL, indicating a lure to disguise the malicious intent. The ML classifier strongly supports the malicious nature of this PDF.

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=greek+and+latin+roots+worksheets+pdf
    • http://files.joh4autism.org/uploads/1/3/2/7/132712209/ffb5897b9.pdf
    • http://juwudizuw.contributewater.com/uploads/1/3/1/0/131069839/giwumubipurujevuw.pdf
    • http://files.hagerbekel.org/uploads/1/3/0/7/130775851/romexejemufeluzod.pdf
    • http://files.capitalchallenge.org/uploads/1/3/1/0/131070590/kutaf.pdf
    • https://cdn.shopify.com/s/files/1/0427/8901/1612/files/bus_eireann_109_timetable.pdf
    • https://cdn.shopify.com/s/files/1/0431/1325/0972/files/fadego.pdf
    • https://cdn.shopify.com/s/files/1/0434/1386/4602/files/64554506171.pdf
    • https://cdn.shopify.com/s/files/1/0429/2935/6959/files/51483342645.pdf
    • https://cdn.shopify.com/s/files/1/0440/5932/8662/files/fomenovi.pdf
    • https://cdn.shopify.com/s/files/1/0433/2732/4310/files/44449909325.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/84712881745.pdf
    • https://cdn.shopify.com/s/files/1/0430/9997/9930/files/68796210692.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/zovoxumaf.pdf
    • https://cdn.shopify.com/s/files/1/0437/2047/4779/files/atomic_science_minecraft.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_off000062c9.bin
b20a5f894ec86c6a84f9f404d5b7e91b8f4eaf6e8dc3e4c38371d5ad2145613d
pdf-font-stream PDF embedded font (sfnt) at offset 0x62C9 5316 bytes
font_01_sfnt_off000074f4.bin
8553b27b48980b1afb366d14b73cbccaadb6e65fd072f7eec24b5920b59fa73c
pdf-font-stream PDF embedded font (sfnt) at offset 0x74F4 10044 bytes