Malicious PDF — malware analysis report

Static analysis result for SHA-256 77161960231a7e6f…

MALICIOUS

PDF

38.8 KB Created: 2020-07-12 12:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a20c52ab0b73d58d3675efe5b1cd53f5 SHA-1: 7e275e2dd13ffaeeb2b37d2e1ec34aa55401a8e2 SHA-256: 77161960231a7e6feeaec5dc32cd659df2890cb0afcca7e6164a624304af0b53
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to WordPress-hosted PDFs, suggesting a link farm or SEO poisoning attempt. One prominent URL, https://ttraff.cc/wb?keyword=renal%20function%20test%20pdf, is identified as a malicious redirector. The document's content, though heavily obfuscated, includes text related to "Renal function test pdf", likely a lure to entice users to click the malicious link. No scripts were extracted from this sample.

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/wb?keyword=renal%20function%20test%20pdf
    • http://files.mariecharpentier.net/uploads/1/3/1/4/131483019/batipaxadas.pdf
    • http://files.rootsoflove.ca/uploads/1/3/1/4/131437446/vemezogijo-fivizosefigif-vojibinepowig-fapurujefamol.pdf
    • http://files.hartig.com/uploads/1/3/2/7/132710683/7804303.pdf
    • http://files.withoutahitchboston.com/uploads/1/3/1/4/131409244/piguw.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://navepepefali.files.wordpress.com/2020/07/kexokixiti.pdf
    • https://nanesufated.files.wordpress.com/2020/06/7486914515.pdf
    • https://gijafodopaw.files.wordpress.com/2020/07/66169996390.pdf
    • https://morixumudiba.files.wordpress.com/2020/07/55158375977.pdf
    • https://lenezofim.files.wordpress.com/2020/06/10053606756.pdf
    • https://jedawixi.files.wordpress.com/2020/06/mesejotawati.pdf
    • https://cdn.shopify.com/s/files/1/0427/4801/8855/files/54483694809.pdf
    • https://cdn.shopify.com/s/files/1/0428/2961/1171/files/wisaxotozelunuzilug.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/89352644259.pdf
    • https://cdn.shopify.com/s/files/1/0429/0458/4355/files/safotifazixivut.pdf
    • https://cdn.shopify.com/s/files/1/0429/8987/9445/files/26564779907.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/suxuteregejo.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_off00005bc8.bin
c4a8f33dbe4b6a2b46acc5d983ac27fe5c6c6ae75bf107ee583d0f9a5f368790
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BC8 4944 bytes
font_01_sfnt_off00006cab.bin
ca95847db74ff335e403e61b2405bc14188a9caf44f219ac956bf95882434d94
pdf-font-stream PDF embedded font (sfnt) at offset 0x6CAB 9872 bytes