Malicious PDF — malware analysis report

Static analysis result for SHA-256 53b91b2db8a0854f…

MALICIOUS

PDF

42.6 KB Created: 2020-08-06 19:48:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 101e7d7dd14488831e2ca3dcbed94c08 SHA-1: bbc74cd8c707605270cdc13b25aa22e23098ebbd SHA-256: 53b91b2db8a0854f8735471848907f89ea5271b52d1bfb4b1ec1a41b2c4e9c36
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many of which point to a link farm hosted on cdn.shopify.com, and one critical link to a known malicious redirector at ttraff.ru. The ML classifier strongly indicated maliciousness. The document body, though heavily obfuscated, contains the URL that is also present in the critical heuristic firing, suggesting a lure to download further content.

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=curso+barras+de+access+pdf
    • http://jajix.zalc.org/uploads/1/3/2/7/132741334/merevi.pdf
    • http://files.umichfishing.com/uploads/1/3/1/4/131406248/kikiduropelenipexojo.pdf
    • http://files.byhisgracehymns.com/uploads/1/3/0/7/130775677/127595ce71bb1.pdf
    • https://cdn.shopify.com/s/files/1/0431/0047/1456/files/kikozuda.pdf
    • https://cdn.shopify.com/s/files/1/0433/1290/6405/files/65813483792.pdf
    • https://cdn.shopify.com/s/files/1/0427/6187/9719/files/jetaperuxefexured.pdf
    • https://cdn.shopify.com/s/files/1/0430/9811/2167/files/wopeboxatavoj.pdf
    • https://cdn.shopify.com/s/files/1/0433/5462/0059/files/wais_iv_manual.pdf
    • https://cdn.shopify.com/s/files/1/0432/6844/0224/files/vogimasuwovepudujebamuk.pdf
    • https://cdn.shopify.com/s/files/1/0439/1505/1163/files/45690613762.pdf
    • https://cdn.shopify.com/s/files/1/0430/9454/0452/files/loderimupup.pdf
    • https://cdn.shopify.com/s/files/1/0431/5696/3479/files/45062133469.pdf
    • https://cdn.shopify.com/s/files/1/0431/2766/8890/files/bocconia_frutescens.pdf
    • https://cdn.shopify.com/s/files/1/0435/9330/2178/files/91248285608.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_off00006544.bin
cf571b539102bb25f00ef174554f0f05abc9d153f85dc2207f2c2b4dfddab9a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x6544 5160 bytes
font_01_sfnt_off000076d6.bin
fc39558efa11bac5a2ba72a4d5d1129924b934d3cda69cc77d90f31ac15c276c
pdf-font-stream PDF embedded font (sfnt) at offset 0x76D6 10976 bytes