Malicious PDF — malware analysis report

Static analysis result for SHA-256 2dc15dc90bb9979d…

MALICIOUS

PDF

42.7 KB Created: 2020-08-15 08:11:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: eb38b3c9f027c5844a986786bd93ff94 SHA-1: 815dec5d0c33586a61a148de3369b0d94f2380df SHA-256: 2dc15dc90bb9979d29fee061391d5c56979260814aead8ad70800017bb9eaedd
154 Risk Score

Malware Insights

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

The PDF contains a high number of embedded links, many of which point to external PDF files hosted on Shopify. One of these links, https://ttraff.cc/wb?keyword=challenging%20word%20problems%20for%20primary%20mathematics%20pdf, is identified as a malicious redirector. The document body, while containing garbled text, also includes this URL and other PDF links, suggesting a link farm or SEO poisoning tactic to drive traffic to malicious infrastructure. The ML classifier strongly flagged this PDF as malicious.

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=challenging%20word%20problems%20for%20primary%20mathematics%20pdf
    • http://difepen.taskgirlbayarea.com/uploads/1/3/1/8/131857419/fifujoterakegela.pdf
    • http://tonof.schizy.org/uploads/1/3/0/8/130814297/libaberinarof_bujawipis_bovejutizexo.pdf
    • http://rifazadat.valdezfoundation.org/uploads/1/3/1/8/131856149/wutigulitedipeso.pdf
    • https://cdn.shopify.com/s/files/1/0429/2860/3295/files/beniwogaragugav.pdf
    • https://cdn.shopify.com/s/files/1/0444/3049/1815/files/72528273066.pdf
    • https://cdn.shopify.com/s/files/1/0432/7640/2854/files/3907547014.pdf
    • https://cdn.shopify.com/s/files/1/0433/7316/6744/files/pdf_biography_of_nelson_mandela.pdf
    • https://cdn.shopify.com/s/files/1/0431/5791/3754/files/seditir.pdf
    • https://cdn.shopify.com/s/files/1/0430/2913/5521/files/food_bioterrorism.pdf
    • https://cdn.shopify.com/s/files/1/0428/7453/6103/files/belimo_actuator_catalogue.pdf
    • https://cdn.shopify.com/s/files/1/0435/7586/9599/files/torazuluwunometajobun.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_off000066fd.bin
cd77eca41ed3ed4e439ed4178bcde14b4d23a7ee3b59c4e5e1437a7f54674e34
pdf-font-stream PDF embedded font (sfnt) at offset 0x66FD 5808 bytes
font_01_sfnt_off00007aa1.bin
48fc1f51951bb103c25298d78ded37ba59a0ee9aeb3027f7257852eb74dcadc8
pdf-font-stream PDF embedded font (sfnt) at offset 0x7AA1 10324 bytes