Malicious PDF — malware analysis report

Static analysis result for SHA-256 b164c074d34aa867…

MALICIOUS

PDF

41.9 KB Created: 2020-08-21 01:11:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 37cd091a76559fad6a82446cae2a418b SHA-1: 5658cac30af1923aa8f2513e76e0b7404baa3dcc SHA-256: b164c074d34aa867f470d80d6dc06bdc99798406d2cb07d5aab9f7efd1374221
152 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier as malicious and contains a significant number of embedded links. One of these links, 'https://ttraff.cc/pify?keyword=dls+18+buttons', points to a known malicious redirector. The document body, though heavily obfuscated, also contains this URL and numerous other links to PDF files hosted on various domains, suggesting a link farm or redirection scheme. The primary attack pattern appears to be the distribution of malicious links disguised within a PDF document.

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=dls+18+buttons
    • http://files.leroyvfw.com/uploads/1/3/1/4/131410158/vabuluni.pdf
    • http://files.anniepoole.com/uploads/1/3/0/8/130813413/3048650.pdf
    • https://cdn.shopify.com/s/files/1/0429/8627/4967/files/mikalamuvetowigaw.pdf
    • https://cdn.shopify.com/s/files/1/0427/8580/0358/files/nikiwubateworaferuraril.pdf
    • https://cdn.shopify.com/s/files/1/0438/4122/4861/files/mimazujudamapewip.pdf
    • https://cdn.shopify.com/s/files/1/0434/3401/6924/files/zovomupopavatawiw.pdf
    • https://cdn.shopify.com/s/files/1/0430/0718/0954/files/84340162386.pdf
    • https://cdn.shopify.com/s/files/1/0432/5657/8212/files/xenomanezumegefofepexatik.pdf
    • https://cdn.shopify.com/s/files/1/0432/7332/2664/files/12560091690.pdf
    • https://cdn.shopify.com/s/files/1/0438/5059/6512/files/sumewenofuk.pdf
    • https://cdn.shopify.com/s/files/1/0430/8205/5842/files/rejibizapob.pdf
    • https://cdn.shopify.com/s/files/1/0432/4638/7367/files/nejenipukapudaxurilani.pdf
    • https://cdn.shopify.com/s/files/1/0432/5765/9560/files/21857781118.pdf
    • https://cdn.shopify.com/s/files/1/0428/6955/5356/files/academic_advisor_cover_letter.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_off0000659d.bin
0d1bd46e6b21dfdb3235045af45c0a9f4ae4549410a96228fa7a56f62bca54c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x659D 4756 bytes
font_01_sfnt_off000075de.bin
f4d017f181fc6b4d7f4a6ad35a3ab5aee23f607b39aa10cfb4428d5657319b15
pdf-font-stream PDF embedded font (sfnt) at offset 0x75DE 11348 bytes