Malicious PDF — malware analysis report

Static analysis result for SHA-256 711992dcb622e422…

MALICIOUS

PDF

42.1 KB Created: 2020-08-30 18:39:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dd6a11713f8fd7dd0dc0c0950bf5a741 SHA-1: e923db671de2fa105a24b4b8b5586a9186b8e948 SHA-256: 711992dcb622e4224a934d8d15eea10f590025e9cb3dbac4c9c0c87b5ac67e1d
162 Risk Score

Malware Insights

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

The PDF contains a link farm and a specific URL pointing to known malicious redirector infrastructure, as indicated by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text related to 'asp net free ebooks pdf' and the malicious URL, suggesting a lure for users interested in such content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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.com/wix?keyword=asp+net+free+ebooks+pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/f80014_aa884c7b57164e7d898c7d1f4ad5a59d.pdf
    • https://static.usrfiles.com/ugd/822ecd_80137f9f0a064bb5a8e5a808e042906e.pdf
    • https://static.usrfiles.com/ugd/1b8612_475005c69df949d1bcc1dc2117660620.pdf
    • https://static.usrfiles.com/ugd/b8c837_72a36348727c4e4a8f130218f187521d.pdf
    • https://static.usrfiles.com/ugd/d775a9_e7098f7548954c5eae557164beefa0a3.pdf
    • https://static.usrfiles.com/ugd/067ecb_d90a3778982141a4a8952eba063c45eb.pdf
    • https://static.usrfiles.com/ugd/b8c837_ee299560ee4442fbb99473f9bbd577f1.pdf
    • https://cdn.shopify.com/s/files/1/0435/9825/0146/files/etiologia_del_asma_bronquial.pdf
    • https://cdn.shopify.com/s/files/1/0439/1541/1608/files/worksheet_writing_numbers_1-_10.pdf
    • https://cdn.shopify.com/s/files/1/0465/3521/3206/files/novadixobozeva.pdf
    • https://static.usrfiles.com/ugd/19103d_3c610c9348a2468690b1dcb152ef97e5.pdf
    • https://static.usrfiles.com/ugd/b8c837_7512fdf9bc5245d49cfd1570251fa20f.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_off00006850.bin
61db8acbbe58f1abc84e0d7e55ed0dee00ea2990bdb4d0adfbcd1edd6d450170
pdf-font-stream PDF embedded font (sfnt) at offset 0x6850 4984 bytes
font_01_sfnt_off0000794e.bin
d4aa43be467b3a197c3ad12050f476f766bdf93a8ac277898c8c6c3f15e668d0
pdf-font-stream PDF embedded font (sfnt) at offset 0x794E 10188 bytes