Malicious PDF — malware analysis report

Static analysis result for SHA-256 88dcac31d3ad1a94…

MALICIOUS

PDF

50.8 KB Created: 2020-08-30 18:02:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dfe1ddbde97fe7772c04a59a304a14ac SHA-1: d8069a68e5f14d6772b275414303691d891077fe SHA-256: 88dcac31d3ad1a94c1341db252dd4a979135696a3edd91bde53371e7741431b7
154 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to 'https://ttraff.cc/wix?keyword=bibliografia+de+libros+de+finanzas+c'. Additionally, another critical heuristic indicates a PDF link farm, with numerous external links, many pointing to 'static.usrfiles.com'. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the same redirector URL, suggesting a lure to a malicious site.

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/wix?keyword=bibliografia+de+libros+de+finanzas+c
    • https://static.usrfiles.com/ugd/b8c837_cd0df82da68746e39996f5a9de575e1d.pdf
    • https://static.usrfiles.com/ugd/b8c837_ca0ca09d60ed4d4681a44e90f1a216d1.pdf
    • https://static.usrfiles.com/ugd/868401_de4ad5a610004859bfec16a27c682136.pdf
    • https://static.usrfiles.com/ugd/b8c837_fd8539a7c5b848be8d4ab155ebe52973.pdf
    • https://static.usrfiles.com/ugd/b8c837_205833fb5abc4c7cbb623d19e83daa11.pdf
    • https://static.usrfiles.com/ugd/f96b02_0becf9bc2b114abf822523bcb6363065.pdf
    • https://static.usrfiles.com/ugd/b8c837_e24ce86c8fa04a588c867cc4fe658ea9.pdf
    • https://static.usrfiles.com/ugd/b8bbd7_223591c7d9f14a5cbbe81304a509c3c1.pdf
    • https://static.usrfiles.com/ugd/90c678_3835f1d8f4b644da8646c3cdabaf9bfc.pdf
    • https://static.usrfiles.com/ugd/8ab72e_764fb13d7f9d4bccbb7ae1d2abbd04a4.pdf
    • https://cdn.shopify.com/s/files/1/0428/3033/2070/files/11340596077.pdf
    • https://cdn.shopify.com/s/files/1/0438/5452/8677/files/juwidibenesuxeb.pdf
    • https://cdn.shopify.com/s/files/1/0427/4959/1718/files/54994989554.pdf
    • https://cdn.shopify.com/s/files/1/0459/2317/2503/files/minutes_template_for_staff_meeting.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_off00008500.bin
032620042ce1f4a1c59d49c5d29243d980f0a040bab28e0717e48189af6602d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x8500 5428 bytes
font_01_sfnt_off00009782.bin
fc7e511e8bb25fe7eab417825e59e4fcb08b2322161ecfe72cbac1f39f334039
pdf-font-stream PDF embedded font (sfnt) at offset 0x9782 11320 bytes