Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e84fc1726e518c4…

MALICIOUS

PDF

55.7 KB Created: 2020-07-30 18:29:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1a663be529e614392e7e372741a664f3 SHA-1: 961f805f80bc5e15e7c5ad40d815c8e9e65fd1d7 SHA-256: 3e84fc1726e518c471a9c2981a95172061052ab52b83612e9d76e0aac4d0fbfb
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a link farm hosted on Shopify. One of these links, 'https://ttraff.ru/pify?keyword=behavioural+science+notes+pdf', is identified as a malicious redirector. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains text related to 'behavioural science notes pdf' and the authoring application 'wkhtmltopdf', suggesting a lure to disguise the malicious links.

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=behavioural+science+notes+pdf
    • http://files.aiwonglawyers.com/uploads/1/3/1/4/131437119/784833.pdf
    • http://files.usk9.com/uploads/1/3/0/8/130874257/tuxefuf_wefunipudul_sapepebexilojup.pdf
    • http://files.rudisrescue.com/uploads/1/3/1/8/131856160/jikaba.pdf
    • https://cdn.shopify.com/s/files/1/0428/7063/6710/files/91623910279.pdf
    • https://cdn.shopify.com/s/files/1/0434/9375/2997/files/malosulagelud.pdf
    • https://cdn.shopify.com/s/files/1/0429/7916/4314/files/xukugodanofubaxemirugemol.pdf
    • https://cdn.shopify.com/s/files/1/0431/9775/9648/files/77180171688.pdf
    • https://cdn.shopify.com/s/files/1/0435/5312/8612/files/7954786742.pdf
    • https://cdn.shopify.com/s/files/1/0435/6902/1089/files/70850967335.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/lomapatigusobotatijizu.pdf
    • https://cdn.shopify.com/s/files/1/0432/1165/3277/files/55106040071.pdf
    • https://cdn.shopify.com/s/files/1/0436/5526/6454/files/26142101287.pdf
    • https://cdn.shopify.com/s/files/1/0432/9242/6405/files/46055930873.pdf
    • https://cdn.shopify.com/s/files/1/0435/5624/1557/files/zasaduwazowofatevewizem.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/56666804065.pdf
    • https://cdn.shopify.com/s/files/1/0429/5468/6630/files/58072849337.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_off00009c61.bin
c0f010dbe6db273a7beef68d2267e3db09d7e49bef94f834ea9696950d1aee8f
pdf-font-stream PDF embedded font (sfnt) at offset 0x9C61 5232 bytes
font_01_sfnt_off0000ae2b.bin
9edcc6487622b75751ef341ae89f4535287d597f964101de49e52277acac1fc6
pdf-font-stream PDF embedded font (sfnt) at offset 0xAE2B 10316 bytes