Malicious PDF — malware analysis report

Static analysis result for SHA-256 144cbc78e6dccc64…

MALICIOUS

PDF

39.8 KB Created: 2020-09-02 12:59:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 603f1054e72b90c1cbad61ec52b0c610 SHA-1: 42b2a63886ffd33db489794a061db9d972679924 SHA-256: 144cbc78e6dccc64ed1a24b4f23ef38612008a1956bcd619705f3e1641dceecb
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many of which point to a redirector service. The document body, though heavily obfuscated, contains a URL that appears to be a lure for educational materials, likely intended to trick users into clicking malicious links. The ML classifier strongly indicates 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.club/wix?keyword=free+common+core+math+worksheets+7th+grade
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b7082a_bdde956013484e19904ce17e06192b94.pdf
    • https://static.usrfiles.com/ugd/6908d7_c4292a4652d34b0eb103b83e62373fd4.pdf
    • https://static.usrfiles.com/ugd/e4f6f0_c2f7d7741255458cabce33f2e369d0c6.pdf
    • https://static.usrfiles.com/ugd/4c3ae3_d0e18e03918c46cfbf531bfb51a8f27d.pdf
    • https://static.usrfiles.com/ugd/225520_32a7b8e1b96546158055627bdc8df327.pdf
    • https://cdn.shopify.com/s/files/1/0439/7416/4638/files/easy_free_pub_quiz_questions_and_answers.pdf
    • https://cdn.shopify.com/s/files/1/0430/7252/0353/files/97338446067.pdf
    • https://cdn.shopify.com/s/files/1/0434/7900/7384/files/digital_electronics_viva_questions.pdf
    • https://cdn.shopify.com/s/files/1/0434/1301/2630/files/internal_audit_duties_and_responsibilities_pdf.pdf
    • https://cdn.shopify.com/s/files/1/0431/4395/4594/files/chhota_bheem_chhota_bheem_free.pdf
    • https://static.usrfiles.com/ugd/4e6dd5_b34dab0cfaa847b0bf83f2c4c30a5962.pdf
    • https://static.usrfiles.com/ugd/de60da_b4d35b0debf74291b4ce26a5586e4408.pdf
    • https://static.usrfiles.com/ugd/974a4e_5740ffa894294cbf8cd221094d88bf1d.pdf
    • https://static.usrfiles.com/ugd/b8c837_1a56a2e8c17b4000b26c132eab328a95.pdf
    • https://static.usrfiles.com/ugd/b8c837_8e52b85748f1468db76280c43edec44d.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005c45.bin
7e50c41311a4cce1a6ed7f2f829f28fec243ddb0e8608e3898ba9c219e06b7a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C45 5512 bytes
font_01_sfnt_off00006ef4.bin
b6e69dd3c89903747c9d27661e66e27b76e4bb8049b589a65fabf15060cffef7
pdf-font-stream PDF embedded font (sfnt) at offset 0x6EF4 10292 bytes