Malicious PDF — malware analysis report

Static analysis result for SHA-256 671b65e1efd870d6…

MALICIOUS

PDF

40.4 KB Created: 2020-08-24 12:49:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4296f00367b694cb5ad849a3faa5d43e SHA-1: b16814a38b3b63869e328349d717c0ef4312fa6c SHA-256: 671b65e1efd870d6bad4b7416e136876a490b4028a5dc5fd99fcf68dab038fde
154 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a malicious URL, disguised as 'annual payroll tax forms'. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK confirms this redirection to known malicious infrastructure. Additionally, the PDF_SEO_LINK_FARM heuristic indicates a large number of outbound links, suggesting a link farm designed to distribute malicious content. No scripts were extracted, but the presence of embedded URLs and the ML classifier's high confidence score support the malicious verdict.

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/pify?keyword=annual+payroll+tax+forms
    • http://walegegut.jessicaohanley.com/uploads/1/3/0/7/130775374/tiwikanadigekezovi.pdf
    • http://files.borderskirental.com/uploads/1/3/1/3/131379833/lemuw.pdf
    • http://files.daphnefatterphd.com/uploads/1/3/1/6/131636957/a96824f4.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0435/7141/3155/files/7097519067.pdf
    • https://cdn.shopify.com/s/files/1/0432/8803/5486/files/2579831203.pdf
    • https://cdn.shopify.com/s/files/1/0435/5984/6051/files/aci_sp_4.pdf
    • https://cdn.shopify.com/s/files/1/0438/0449/1936/files/60378641450.pdf
    • https://cdn.shopify.com/s/files/1/0433/4950/8246/files/bapalujuzapobujojuk.pdf
    • https://cdn.shopify.com/s/files/1/0435/7180/6366/files/corpse_bride_piano.pdf
    • https://cdn.shopify.com/s/files/1/0432/9770/2046/files/e_bildirge_ifre_formu.pdf
    • https://cdn.shopify.com/s/files/1/0447/3788/8410/files/pulse_code_modulation_techniques.pdf
    • https://cdn.shopify.com/s/files/1/0432/3026/5511/files/30883582472.pdf
    • https://cdn.shopify.com/s/files/1/0437/2316/1768/files/sinubufevav.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_off00005ec1.bin
f55680cee4efe2b5fe0297e92a44abff5b1ce2fab533532839be390b7b7cb5d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x5EC1 5204 bytes
font_01_sfnt_off0000706e.bin
ecd3495469a90d799386c085ad345baa41d263d968d064c57ddfa8b3b6e78b90
pdf-font-stream PDF embedded font (sfnt) at offset 0x706E 10980 bytes