Malicious PDF — malware analysis report

Static analysis result for SHA-256 caca13943970e2cc…

MALICIOUS

PDF

40.7 KB Created: 2020-08-08 21:59:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3878afaf58ac4998cce9540b91ae3ae3 SHA-1: dce88e3f6e8ec33eb3772a53f5a9176440f1b6ef SHA-256: caca13943970e2cc790943ec9448e6282ed5357670c56002ac180d012879dc51
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by an ML classifier with high confidence. It contains a significant number of embedded links, with one identified as a known malicious redirector. The document body, though heavily obfuscated, contains references to the malicious URL and appears to be generated by wkhtmltopdf, a tool often used to create PDF documents from web content. The presence of a link farm suggests an attempt to lure users to malicious infrastructure.

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=actor+s+nightmare+script+pdf
    • http://files.collectifcontraceptionliege.com/uploads/1/3/0/7/130740013/2094605.pdf
    • http://files.centexautomotiverestoration.com/uploads/1/3/0/7/130739280/mojuwadetubiga-lefasel.pdf
    • http://files.matthewfleckenstein.com/uploads/1/3/1/6/131606201/04bcfa4c.pdf
    • http://files.aoemedia.tv/uploads/1/3/0/8/130873820/6159849.pdf
    • https://cdn.shopify.com/s/files/1/0437/6500/6494/files/rebokudagogibuxaxuvegegul.pdf
    • https://cdn.shopify.com/s/files/1/0439/8468/3166/files/lawejaforofipa.pdf
    • https://cdn.shopify.com/s/files/1/0430/7140/6237/files/27123235127.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/61411835552.pdf
    • https://cdn.shopify.com/s/files/1/0427/8091/7926/files/70188788718.pdf
    • https://cdn.shopify.com/s/files/1/0437/8443/7922/files/path_2_1_7_5_7.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/jepomosojavadoji.pdf
    • https://cdn.shopify.com/s/files/1/0431/5299/8556/files/sarizegawese.pdf
    • https://cdn.shopify.com/s/files/1/0433/9662/8641/files/bike_spare_parts_name_list_with_images.pdf
    • https://cdn.shopify.com/s/files/1/0430/3863/8241/files/applied_mathematics_2_notes.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_off00006070.bin
bd8e4352d6ae3140bd7521f8895932efdbe65cbe3b32615e231df8875a4300c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x6070 5528 bytes
font_01_sfnt_off00007311.bin
24485d6d07972392991bf325f31e8c64c3bf0a6bcbd168cbfbffea6065661dea
pdf-font-stream PDF embedded font (sfnt) at offset 0x7311 10280 bytes