Malicious PDF — malware analysis report

Static analysis result for SHA-256 39c49583bbf7a3a1…

MALICIOUS

PDF

49.2 KB Created: 2020-07-28 17:47:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d1707db0b42c2b03424e99facb4f6c89 SHA-1: 802d4c9815481228f12f3f41ed4fe9bb0decad66 SHA-256: 39c49583bbf7a3a17b98fa754c673296369ed7a2a4a9b02519cfbd5e8fac216e
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with the primary heuristic identifying a link to a known malicious redirector. The document body, though heavily obfuscated, contains text related to exceptions and wkhtmltopdf, suggesting it's a lure. 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.ru/pify?keyword=nested+exception+is+java.+lang.+numberformatexception
    • http://files.buildteacherhub.org/uploads/1/3/1/4/131406505/8552289.pdf
    • http://files.save4salud.com/uploads/1/3/0/8/130813458/4218209.pdf
    • http://files.sdena.org/uploads/1/3/1/8/131871850/557dcb45b0610aa.pdf
    • https://cdn.shopify.com/s/files/1/0429/5163/9196/files/serorolepuruxefebibuwu.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/89573664631.pdf
    • https://cdn.shopify.com/s/files/1/0431/1266/1152/files/vodewotubumodagesegikatup.pdf
    • https://cdn.shopify.com/s/files/1/0431/3301/0081/files/90822143383.pdf
    • https://cdn.shopify.com/s/files/1/0429/1792/0934/files/nirufebadupexiwa.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/9467339244.pdf
    • https://cdn.shopify.com/s/files/1/0431/2619/4342/files/varizemumekikelix.pdf
    • https://cdn.shopify.com/s/files/1/0434/7147/0742/files/delalofeze.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/76106621034.pdf
    • https://cdn.shopify.com/s/files/1/0434/0881/8333/files/jekibaledu.pdf
    • https://cdn.shopify.com/s/files/1/0429/2991/4012/files/18458644561.pdf
    • https://cdn.shopify.com/s/files/1/0429/1058/0903/files/20566230371.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_off00007faa.bin
2b557b6593865da601abe3b27e963c360bf4eb606f8c32faf206508898429faf
pdf-font-stream PDF embedded font (sfnt) at offset 0x7FAA 5704 bytes
font_01_sfnt_off00009310.bin
fb0f91d8f7d6292e0eb1d57f5e6efd382116eaa0c0f4e57d3cc82b08bffd72e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x9310 10564 bytes