Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a03587d394ce674…

MALICIOUS

PDF

46.9 KB Created: 2020-08-18 19:46:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ecad3ab8ef8227543f29d5e7d0f951e9 SHA-1: 5fb21164dfe6a4466d88a038c60737dc5e22b061 SHA-256: 8a03587d394ce6742247ffd04e16640e12be52a3833853a8f57c4308cc5bf82a
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many of which point to Shopify domains hosting other PDFs, but a critical heuristic identified a link to a known malicious redirector. The document body, though heavily obfuscated, contains text related to 'free worksheets for elementary students' and the malicious redirector URL, suggesting a lure to trick users into clicking the links. The presence of a malicious redirector and the SEO-like link farm structure indicate a phishing or scam attempt.

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=free+worksheets+for+elementary+students
    • http://xokunema.hhsmusicboosters.com/uploads/1/3/0/9/130969335/xarinovebiku.pdf
    • http://files.spanish-charts.com/uploads/1/3/1/8/131856706/sagosidukew_jojalogopit_bolat.pdf
    • https://cdn.shopify.com/s/files/1/0430/3729/4741/files/ziwawugexig.pdf
    • https://cdn.shopify.com/s/files/1/0428/0070/9791/files/kelovovobirivadame.pdf
    • https://cdn.shopify.com/s/files/1/0431/6948/0866/files/23533437006.pdf
    • https://cdn.shopify.com/s/files/1/0433/9374/5046/files/xajotegus.pdf
    • https://cdn.shopify.com/s/files/1/0432/6565/4939/files/28102420873.pdf
    • https://cdn.shopify.com/s/files/1/0427/9749/8535/files/plus_two_zoology_notes.pdf
    • https://cdn.shopify.com/s/files/1/0429/6962/8828/files/how_to_run_shell_file.pdf
    • https://cdn.shopify.com/s/files/1/0432/3088/8094/files/totojukafeditupokatom.pdf
    • https://cdn.shopify.com/s/files/1/0434/2457/9736/files/woxituzoruwokekogazedaf.pdf
    • https://cdn.shopify.com/s/files/1/0430/0469/0581/files/65947764313.pdf
    • https://cdn.shopify.com/s/files/1/0432/9160/7190/files/nesisopesarejekegejusis.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_off00007a36.bin
5a4ee0650fa12f048efcd1c4718ffe64640fd1316226d02aed415a5882e21dcf
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A36 5360 bytes
font_01_sfnt_off00008c62.bin
9878c6a7c234126f57d5ecbc7857ef159d12f3304974f49b465879cb2e722246
pdf-font-stream PDF embedded font (sfnt) at offset 0x8C62 10220 bytes