Malicious PDF — malware analysis report

Static analysis result for SHA-256 50c87a721c6a3966…

MALICIOUS

PDF

41.1 KB Created: 2020-08-14 22:47:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cf82b3a425d70f9f51243e3e296d4b4d SHA-1: 3f1d0e078151aba0cfc0d97cd2a4dea61cc84e28 SHA-256: 50c87a721c6a3966cee9e346d629ed5f7be479f639fc00b095ec63754552aad3
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to `ttraff.ru`. Additionally, it exhibits characteristics of a PDF link farm, with numerous embedded links, many of which point to benign Shopify domains but one critical link to `ttraff.ru`. The ML classifier also strongly flagged this PDF as malicious. The primary attack vector appears to be social engineering via a malicious link embedded within the document.

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/wb?keyword=break%20even%20point%20chapter%20pdf
    • http://bufija.adamkaszycki.com/uploads/1/3/2/8/132814930/6367264.pdf
    • http://files.stephanie-hixon.com/uploads/1/3/1/6/131606331/3792846.pdf
    • https://cdn.shopify.com/s/files/1/0428/7922/1927/files/62074834564.pdf
    • https://cdn.shopify.com/s/files/1/0438/5082/5893/files/fundamentals_of_fluid_mechanics_munson.pdf
    • https://cdn.shopify.com/s/files/1/0437/1241/3851/files/79366049918.pdf
    • https://cdn.shopify.com/s/files/1/0430/0269/1743/files/cfop_f2l.pdf
    • https://cdn.shopify.com/s/files/1/0450/7625/0776/files/lapidevezebigoxogazuruz.pdf
    • https://cdn.shopify.com/s/files/1/0430/0292/1111/files/52473351503.pdf
    • https://cdn.shopify.com/s/files/1/0432/2358/0831/files/foramisegogibovi.pdf
    • https://cdn.shopify.com/s/files/1/0454/8021/4678/files/lines_written_a_few_miles_above_tintern_abbey.pdf
    • https://cdn.shopify.com/s/files/1/0431/6259/9583/files/71035014512.pdf
    • https://cdn.shopify.com/s/files/1/0431/6486/0575/files/behavior_modification_principles_and_procedures_5th_edition_free.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_off00006278.bin
befcf57d7b065268155f7b862af08cd55e7b18437c899c1811b8f069a97a8c99
pdf-font-stream PDF embedded font (sfnt) at offset 0x6278 5204 bytes
font_01_sfnt_off0000742d.bin
ad34f5905d055a7fa5dee8fc2e5d0548514f028d664bfdbde3e28c7ea2a7a792
pdf-font-stream PDF embedded font (sfnt) at offset 0x742D 10572 bytes