Malicious PDF — malware analysis report

Static analysis result for SHA-256 55fbdea1b4989930…

MALICIOUS

PDF

39.7 KB Created: 2020-08-22 16:17:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d8c285ba4b283c9f79345d6377cdd4dc SHA-1: c75bb66a66f2479bde6b0f666a57f5fb2f82eace SHA-256: 55fbdea1b49899300965f3517e3a8b2043591cf1e69ae28d7c87ffa28bc5c0b6
152 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a known malicious infrastructure, as indicated by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains the URL that leads to the redirector. The PDF also functions as a link farm, pointing to numerous external PDFs, likely to manipulate search engine results or distribute further malicious content. The ML classifier strongly flagged this PDF as malicious.

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.cc/pify?keyword=disability+awareness+merit+badge+worksheet+answers
    • http://files.narokgames.com/uploads/1/3/0/7/130776769/871812.pdf
    • http://xuxok.woodfiredpizza.org/uploads/1/3/1/6/131606620/jibutadadisoj_tililuwej_tugew_fixuleb.pdf
    • https://cdn.shopify.com/s/files/1/0438/2598/7734/files/kigejigulikususosinumanuj.pdf
    • https://cdn.shopify.com/s/files/1/0437/4190/5050/files/pathophysiology_of_bronchial_asthma.pdf
    • https://cdn.shopify.com/s/files/1/0429/0304/4263/files/49818772065.pdf
    • https://cdn.shopify.com/s/files/1/0435/4372/4186/files/6117971384.pdf
    • https://cdn.shopify.com/s/files/1/0437/6110/7105/files/beating_the_street_ebook.pdf
    • https://cdn.shopify.com/s/files/1/0431/7780/3931/files/paxerewejarisitoz.pdf
    • https://cdn.shopify.com/s/files/1/0429/0802/4985/files/9367236934.pdf
    • https://cdn.shopify.com/s/files/1/0432/5117/1478/files/42576547376.pdf
    • https://cdn.shopify.com/s/files/1/0439/0676/0856/files/15490487570.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/
    • https://cdn.shopify.com/s/files/1/0437/6110/7105/files/beating_the

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005ce4.bin
b4500a67af1c1a602b90e05886410c299851826564e1280051c9c99b17055463
pdf-font-stream PDF embedded font (sfnt) at offset 0x5CE4 5636 bytes
font_01_sfnt_off00006ff2.bin
3fc755067b758f3090a5ff722794d61c51c38c0afbcc2749c7f4969c3295d4e5
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FF2 9812 bytes