Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d54894fa1a4797f…

MALICIOUS

PDF

44.7 KB Created: 2020-08-20 02:05:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0ea3b823890dea14d496bb6a023eb922 SHA-1: 8eecf56bb14d7d585c253f1b47346ab2d21f6414 SHA-256: 4d54894fa1a4797f81b83ea5fbda142f9e451fce5193bc4a9671df21fe3c6557
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 pointing to Shopify domains, but one critical link directs to a known malicious redirector. The document body, though heavily obfuscated, contains text related to 'factoring trinomials pdf worksheet' and the malicious URL, suggesting a lure to a phishing or malware distribution site. 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.com/pify?keyword=factoring+trinomials+pdf+worksheet
    • http://files.thechurch1689.com/uploads/1/3/0/8/130814124/zifunimerezekul-pajozosefilexe.pdf
    • http://files.stonesj.org/uploads/1/3/1/8/131871864/6428906.pdf
    • http://files.giltnercustomer.com/uploads/1/3/1/6/131606069/9999661.pdf
    • https://cdn.shopify.com/s/files/1/0429/9682/6273/files/35358868258.pdf
    • https://cdn.shopify.com/s/files/1/0440/6935/5670/files/canon_in_d_guitar_tab_easy.pdf
    • https://cdn.shopify.com/s/files/1/0427/8986/3580/files/91281440812.pdf
    • https://cdn.shopify.com/s/files/1/0432/5038/5051/files/psicologia_papalia.pdf
    • https://cdn.shopify.com/s/files/1/0434/0006/9283/files/66970186002.pdf
    • https://cdn.shopify.com/s/files/1/0448/2108/6365/files/iphone_app_store_apk_for_android.pdf
    • https://cdn.shopify.com/s/files/1/0434/1887/8117/files/tixurefigowe.pdf
    • https://cdn.shopify.com/s/files/1/0433/0032/3478/files/16457358875.pdf
    • https://cdn.shopify.com/s/files/1/0430/6976/7831/files/74677198643.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000627a.bin
4be6b8ce14b5830fee58077a95fef58cf8f3b13980d28f356a9ac5774f75e084
pdf-font-stream PDF embedded font (sfnt) at offset 0x627A 5468 bytes
font_01_sfnt_off000074f4.bin
36e1185b9e48c7f3185c8306c07ad156059c4a13a7a3d11bc0ef965029a0e7e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x74F4 10264 bytes
font_02_sfnt_off00009814.bin
ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x9814 4324 bytes