Malicious PDF — malware analysis report

Static analysis result for SHA-256 21c39242bd73ec44…

MALICIOUS

PDF

47.3 KB Created: 2020-08-13 07:08:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2da82511e45aa54f6b926dafca9c5ae9 SHA-1: f2e7d221d52be86a470e8e421f14a65a7bccf366 SHA-256: 21c39242bd73ec4497d93d9f388e74a450436767d91b59547cee0dd6698b1b2f
152 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with a critical heuristic firing indicating it's a malicious redirector and a link farm. The primary malicious link, 'https://ttraff.ru/wb?keyword=android%20java%20open%20pdf', is designed to lure users by appearing to offer information on 'Android java open pdf'. The document body, though heavily obfuscated, also contains this URL, reinforcing the lure. 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.ru/wb?keyword=android%20java%20open%20pdf
    • http://files.themonkeysbanana.com/uploads/1/3/2/7/132711966/pagupabigun.pdf
    • http://files.monstereventsonline.com/uploads/1/3/0/7/130738924/1627828.pdf
    • http://files.mainecela.org/uploads/1/3/0/7/130776002/rajuxelowolimu.pdf
    • http://files.longcreekschool.com/uploads/1/3/1/4/131406036/8237860.pdf
    • https://cdn.shopify.com/s/files/1/0431/9635/0624/files/lukekadetodupozizirus.pdf
    • https://cdn.shopify.com/s/files/1/0432/2181/1362/files/tevoradetefetomele.pdf
    • https://cdn.shopify.com/s/files/1/0431/8704/4515/files/tanoxosu.pdf
    • https://cdn.shopify.com/s/files/1/0427/5650/5756/files/zinekaza.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/55497749658.pdf
    • https://cdn.shopify.com/s/files/1/0437/0087/9515/files/xowuwelopoka.pdf
    • https://cdn.shopify.com/s/files/1/0431/7400/2848/files/wutuwolebuluwe.pdf
    • https://cdn.shopify.com/s/files/1/0430/0092/2261/files/potoximi.pdf
    • https://cdn.shopify.com/s/files/1/0438/0885/0081/files/39107617672.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_off00006f5e.bin
52aa190e99c240318c4f97798655b768b04cca4da77fc286a9a39d6d40a0d4fb
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F5E 4660 bytes
font_01_sfnt_off00007f3d.bin
963c5d1e207790101f5f38a3a2c0ffc5f0b9403cea454cfde8d35723aa125113
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F3D 10352 bytes
font_02_sfnt_off0000a29c.bin
1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e
pdf-font-stream PDF embedded font (sfnt) at offset 0xA29C 4324 bytes