Malicious PDF — malware analysis report

Static analysis result for SHA-256 139cb5bbe96161af…

MALICIOUS

PDF

38.8 KB Created: 2020-08-30 13:11:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 36d84cee3412b142204bcd584e166858 SHA-1: 3c5bad502c893782490797ec6004ea96dfc903df SHA-256: 139cb5bbe96161afeec7f8b5bd349af9fc8999cf9ea04174d0668ac19f7fc265
154 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded links, many of which point to external PDF files, forming a link farm. One of the primary links directs to a known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL that leads to the malicious redirector, suggesting an attempt to trick users into clicking it. No scripts were extracted, but the presence of embedded URLs and the heuristic firings strongly indicate a malicious intent to redirect users to harmful content.

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/wix?keyword=4+pics+1+word+416
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_16ebe99b704746ec9d98455de98a22e5.pdf
    • https://static.usrfiles.com/ugd/738632_6687e652cd094a60ae89200816ee682f.pdf
    • https://static.usrfiles.com/ugd/078c79_aba0de76ff844640a1162d2a3ddd9f47.pdf
    • https://static.usrfiles.com/ugd/65b209_7a289791946247e3bd009ba0132cbe0c.pdf
    • https://cdn.shopify.com/s/files/1/0437/1070/9913/files/tv_guide_madison.pdf
    • https://cdn.shopify.com/s/files/1/0462/7519/9136/files/web_application_templates_bootstrap_free.pdf
    • https://cdn.shopify.com/s/files/1/0433/0668/0484/files/felipajadifog.pdf
    • https://static.usrfiles.com/ugd/b8c837_712dbd5c204d4b4094da27ff0538d1a6.pdf
    • https://static.usrfiles.com/ugd/74a852_e99864830b2c4b8da0eca20c27edd747.pdf
    • https://cdn.shopify.com/s/files/1/0432/1535/6067/files/99118277732.pdf
    • https://cdn.shopify.com/s/files/1/0454/8486/7736/files/chakmanjo_weather_report.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_off00005b00.bin
16645b53db71a0c5b297d5d1b538b39dc0e9abb84eb70c6cee66dbf2fc7309ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B00 5116 bytes
font_01_sfnt_off00006c8e.bin
543162e986d4bb918ef9457b64f1748dae00c0c68626ebbc86e39908e0129e14
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C8E 10068 bytes