Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecb75e70861737ea…

MALICIOUS

PDF

44.1 KB Created: 2020-08-17 11:38:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 338cb64ec843b20bb85c2d889bc042b2 SHA-1: f8e4b46cb18c6c63c16d72b8ad4d1c4f1a388572 SHA-256: ecb75e70861737ea5281c17529cf184ab108f8df3860bacab852922f48e4665b
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains a large number of embedded links, many pointing to Shopify domains hosting other PDFs, but one critical link directs to a known malicious redirector. The document body, though partially corrupted, contains text suggesting it is an 'answer key', a common lure. The ML classifier strongly flagged this PDF as malicious. The primary malicious URL is https://ttraff.cc/pify?keyword=cet+2019+answer+key+mathematics, which is likely used to redirect the user to a malicious site.

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=cet+2019+answer+key+mathematics
    • http://pipon.evapfaff.com/uploads/1/3/1/4/131437252/texag-munuba.pdf
    • http://vekeded.if-airfranceklmva.com/uploads/1/3/0/8/130874524/6003601.pdf
    • http://files.americansinger.com/uploads/1/3/0/7/130776060/6d3f398d55ff.pdf
    • https://cdn.shopify.com/s/files/1/0435/2799/5552/files/76513493200.pdf
    • https://cdn.shopify.com/s/files/1/0427/7826/3718/files/38024671756.pdf
    • https://cdn.shopify.com/s/files/1/0431/7573/9553/files/robotech_rpg_download.pdf
    • https://cdn.shopify.com/s/files/1/0431/5676/6882/files/30127725211.pdf
    • https://cdn.shopify.com/s/files/1/0432/1925/5454/files/6645189180.pdf
    • https://cdn.shopify.com/s/files/1/0431/1279/2225/files/giviridupufaselutolepam.pdf
    • https://cdn.shopify.com/s/files/1/0436/0785/1171/files/59037023958.pdf
    • https://cdn.shopify.com/s/files/1/0440/6778/2808/files/3677559317.pdf
    • https://cdn.shopify.com/s/files/1/0440/8537/9237/files/zuxabajegiwuge.pdf
    • https://cdn.shopify.com/s/files/1/0440/3150/8645/files/zopow.pdf
    • https://cdn.shopify.com/s/files/1/0430/9280/3744/files/togotonawesidifananizuku.pdf
    • https://cdn.shopify.com/s/files/1/0432/3213/3278/files/16634142462.pdf
    • https://cdn.shopify.com/s/files/1/0440/2806/7990/files/21017598805.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_off00006d8f.bin
283f1e4f203bc0a113a1b2f6091d7dbf726774ca4b64ad77e0d4c21ae0016edc
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D8F 5652 bytes
font_01_sfnt_off000080af.bin
4f58fa04e77d7f6e1c0417e65f0d06c8680bed6eb0c0ead5071e45b9b2b54c5c
pdf-font-stream PDF embedded font (sfnt) at offset 0x80AF 10236 bytes