Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b23c3844daa6b0e…

MALICIOUS

PDF

43.7 KB Created: 2020-09-07 13:18:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 20b6e40e8bbfa5a440d9918a418713ff SHA-1: a82a9ab8805aef5f1616977a9387c0becaaad3c4 SHA-256: 4b23c3844daa6b0e3b9ffb709bbf536ef764ac69291b64ff05fb8deac8eb38d8
154 Risk Score

Malware Insights

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

This PDF document contains a mass external PDF link farm, with many links pointing to Shopify domains, but crucially includes a link to a known malicious redirector. The document body, though heavily obfuscated, contains the text 'Figures of speech worksheet for grade 5' and the malicious URL, suggesting a lure to disguise the malicious intent. The primary malicious IOC is the redirector URL, which likely leads to further malicious content or phishing pages.

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.club/wix?keyword=figures+of+speech+worksheet+for+grade+5
    • https://cdn.shopify.com/s/files/1/0433/9551/4535/files/53120569351.pdf
    • https://cdn.shopify.com/s/files/1/0428/5690/6918/files/19670595.pdf
    • https://cdn.shopify.com/s/files/1/0434/8978/8069/files/30589278982.pdf
    • https://cdn.shopify.com/s/files/1/0434/0645/9032/files/65863093437.pdf
    • https://cdn.shopify.com/s/files/1/0433/1382/3909/files/92319910372.pdf
    • https://static.usrfiles.com/ugd/384ea4_9b914a72c2804380958640c741af9456.pdf
    • https://static.usrfiles.com/ugd/8de238_5b933b0cd7c64b47a08e71bb81bde7b3.pdf
    • https://static.usrfiles.com/ugd/4c1554_3801488d56ee4364a30ebdef3b70a938.pdf
    • https://cdn.shopify.com/s/files/1/0431/8121/1810/files/app_store_apk_android_2._3.pdf
    • https://cdn.shopify.com/s/files/1/0467/9709/5063/files/principios_de_conteo_en_preescolar_segun_baroody.pdf
    • https://cdn.shopify.com/s/files/1/0450/6664/9750/files/aromaterapia_egipcia.pdf
    • https://cdn.shopify.com/s/files/1/0430/4509/3533/files/vixisozi.pdf
    • https://cdn.shopify.com/s/files/1/0433/7064/3614/files/77612254103.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_off00005f28.bin
d8b6d87a42d4571536a1ed64527d393f690f364df54161a2fde7f9054cfeeac9
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F28 5396 bytes
font_01_sfnt_off000071ba.bin
0b11841948ddc9722e1cff1d5224e18b122e79d3b67869bd7e11deffa7a0111e
pdf-font-stream PDF embedded font (sfnt) at offset 0x71BA 10008 bytes
font_02_sfnt_off000093e0.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x93E0 4324 bytes