Malicious PDF — malware analysis report

Static analysis result for SHA-256 c18fb4554d81f489…

MALICIOUS

PDF

49.3 KB Created: 2020-07-09 06:49:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: da37635f62b58e33ba7f9ccef246f92e SHA-1: bd3625479c64f31eb932377aa8cecae54086067a SHA-256: c18fb4554d81f4899fc65788e39864e46a771c866fed493ab05a6230fc89d7bd
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link T1059.001 PowerShell

This PDF document employs a link farm technique, embedding numerous links to external PDF files, likely to manipulate search engine rankings or distribute malicious content. One prominent link directs to a known malicious redirector, ttraff.com, which in turn uses a keyword related to an answer key to lure victims. The ML classifier strongly indicates maliciousness, and the PDF structure with embedded links supports a social engineering attack pattern.

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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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/wb?keyword=composition%20empirical%20and%20molecular%20formulas%20worksheet%20answer%20key In PDF document text
    • http://files.nejnamc.org/uploads/1/3/1/6/131607346/bujowadatasivo.pdfIn PDF document text
    • http://files.sbafootball.org/uploads/1/3/2/8/132814768/kuzekajide.pdfIn PDF document text
    • http://files.arieannamulderphotography.com/uploads/1/3/1/4/131408528/9384165.pdfIn PDF document text
    • http://files.markshteller.com/uploads/1/3/1/0/131070527/8338419.pdfIn PDF document text
    • http://files.centeredbodywork.com/uploads/1/3/1/4/131408528/3638666.pdfIn PDF document text
    • http://files.marvinsnider.com/uploads/1/3/0/7/130739174/fatewor-naxeloke-kaguv.pdfIn PDF document text
    • http://files.ccmooresville.com/uploads/1/3/1/3/131381819/tanupip.pdfIn PDF document text
    • http://files.amilawsmd.com/uploads/1/3/1/6/131606202/4093527.pdfIn PDF document text
    • http://files.thanksamillionimports.com/uploads/1/3/1/6/131606819/xodifuluvukotike.pdfIn PDF document text
    • http://files.livinggodsmission.com/uploads/1/3/0/8/130874413/femobupowufebekoluta.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://tokejar.files.wordpress.com/2020/07/19731973796.pdfIn PDF document text
    • https://kikinanatus.files.wordpress.com/2020/07/gotamivemabagonozotob.pdfIn PDF document text
    • https://kafabumifo.files.wordpress.com/2020/07/razijijipuv.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/29878061118.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/pegumi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/japoxotoruzub.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/dijovosulodomozov.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/pafinekumukomotutawewokab.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000770d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x770D 5560 bytes
SHA-256: 456645248c1ee5cd0411f82bb98827c34a07a7eaccffb2952d327dca5e4ed0da
font_01_sfnt_off000089dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x89DC 14340 bytes
SHA-256: 6d2a56dc9b82663ab36ac57c8ad5b4a72fef9d3171cee31c1ee6935a0534d13c