Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a57cf792882881…

MALICIOUS

PDF

34.0 KB Created: 2020-08-14 13:53:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d2b3883625a529aeed342ba6472f2898 SHA-1: c5887e02949add79405889f49bea1cd2f9098475 SHA-256: a7a57cf7928828811a6fa11fd1454ddd9e0c43c49fe33e1eee20f8303cb54932
152 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as an educational worksheet, aiming to lure users to potentially harmful content. It also features a link farm of numerous SEO-optimized PDFs hosted on Shopify, likely to improve search engine ranking and distribute the malicious payload. The ML classifier strongly indicated maliciousness.

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/wb?keyword=amoeba%20sisters%20video%20recap%20viruses%20worksheet
    • http://files.dawnasdesignthreads.com/uploads/1/3/1/8/131871740/5404484.pdf
    • http://files.spudichlabyale.org/uploads/1/3/0/7/130776673/cd8a6.pdf
    • http://niboduvi.asia-days.com/uploads/1/3/0/7/130739835/959b4a6e58f0d05.pdf
    • https://cdn.shopify.com/s/files/1/0432/9937/3214/files/caderno_de_desenhos_para_pintar.pdf
    • https://cdn.shopify.com/s/files/1/0429/9862/8501/files/pofabaderaratiwunam.pdf
    • https://cdn.shopify.com/s/files/1/0448/3599/5808/files/windstad_manor_mod.pdf
    • https://cdn.shopify.com/s/files/1/0432/5166/3012/files/media_and_information_literacy_definition.pdf
    • https://cdn.shopify.com/s/files/1/0429/8866/7034/files/gasezal.pdf
    • https://cdn.shopify.com/s/files/1/0434/1117/7629/files/worksheets_activities_rime_of_the_ancient_mariner.pdf
    • https://cdn.shopify.com/s/files/1/0436/3943/9510/files/french_to_english_textbook.pdf
    • https://cdn.shopify.com/s/files/1/0430/7202/8823/files/7570195472.pdf
    • https://cdn.shopify.com/s/files/1/0437/3243/5093/files/bevorizi.pdf
    • https://cdn.shopify.com/s/files/1/0437/4750/8385/files/77361489812.pdf
    • https://cdn.shopify.com/s/files/1/0433/2965/0843/files/47501952789.pdf
    • https://cdn.shopify.com/s/files/1/0430/3123/2674/files/brute_force_attack_tutorial.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_off00004803.bin
f327c198eaa6cf7aef0383611960e3e78a515356aa9a64263d6f5d7952db475c
pdf-font-stream PDF embedded font (sfnt) at offset 0x4803 5628 bytes
font_01_sfnt_off00005b0d.bin
a736a569ec3d4f0149d374c345ba901a5d3f4224d7e79dc097f77c4689182af1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B0D 9308 bytes