Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a9a889ae65ad0e5…

MALICIOUS

PDF

40.0 KB Created: 2020-08-20 08:30:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2c8073c1ba6bb6c38a78374418b3e471 SHA-1: 528a1754ee07cbcb51f87b054da51c44db12e314 SHA-256: 2a9a889ae65ad0e5249501ec7edffe92d329333c9aaebfc056eef23ee8d91322
154 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a known malicious infrastructure, identified by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text related to 'linear motion problems worksheet' and the malicious URL. The ML classifier also strongly indicated maliciousness. The primary attack vector appears to be a social engineering lure to a malicious redirector.

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.ru/pify?keyword=linear+motion+problems+worksheet
    • http://files.acdelre.com/uploads/1/3/1/3/131379706/gimeruwer.pdf
    • http://files.bilgerdesign.net/uploads/1/3/1/3/131380032/tivopadosogis-dixiva-gixugedo-sugoxupevuku.pdf
    • http://files.sophiceramics.com/uploads/1/3/1/1/131163859/ribobarezakib-sedowojaxujozed-galezisez-nabogudipa.pdf
    • https://cdn.shopify.com/s/files/1/0438/8113/6296/files/php_clear_opcache.pdf
    • https://cdn.shopify.com/s/files/1/0428/1332/5471/files/lozuvituguserurusi.pdf
    • https://cdn.shopify.com/s/files/1/0431/2183/6193/files/dawejajirizutumozub.pdf
    • https://cdn.shopify.com/s/files/1/0436/9140/9562/files/lexun.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/vixegenosevisime.pdf
    • https://cdn.shopify.com/s/files/1/0428/8489/0790/files/9457294336.pdf
    • https://cdn.shopify.com/s/files/1/0434/1045/6730/files/kelley_mooney_hallelujah_lyrics.pdf
    • https://cdn.shopify.com/s/files/1/0431/4192/2982/files/exponential_equation_solving_with_logarithms_worksheet.pdf
    • https://cdn.shopify.com/s/files/1/0431/4647/7725/files/tubalimedepogexisazenixi.pdf
    • https://cdn.shopify.com/s/files/1/0434/0455/8488/files/metro_pcs_ringtones._com.pdf
    • https://cdn.shopify.com/s/files/1/0432/6054/3138/files/momavamuraxupu.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/70278744099.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_off00005de2.bin
266b05766802042f6b0627ad70211f14448cfde37054c1f47410fbcd41196aab
pdf-font-stream PDF embedded font (sfnt) at offset 0x5DE2 5296 bytes
font_01_sfnt_off00006fc4.bin
379297a50271b3feecda7110d953295b176ed6745f54d33afc1870849fcd5202
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FC4 10476 bytes