Malicious PDF — malware analysis report

Static analysis result for SHA-256 92bf6a775dbde5c8…

MALICIOUS

PDF

49.3 KB Created: 2020-08-05 23:28:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc4454cfb8107f8008eba3431075be3c SHA-1: bcba4906e48184526dd6a4b0f75d3feef332f826 SHA-256: 92bf6a775dbde5c855c70cd1d34420b70d45799749fdb9e6c817a2a8a69de14f
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for linking to known malicious redirector infrastructure, specifically to a URL related to 'spinal cord injury rehabilitation protocol pdf'. The document body, though heavily obfuscated, contains the same URL, indicating a lure to a malicious site. The PDF also exhibits characteristics of a link farm, with numerous embedded URLs pointing to external resources, many of which are hosted on Shopify. The ML classifier strongly supports the malicious nature of this PDF.

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.com/pify?keyword=spinal+cord+injury+rehabilitation+protocol+pdf
    • http://files.thewasting.com/uploads/1/3/1/0/131070539/judosuwumudoza.pdf
    • http://files.treetogrow.com/uploads/1/3/0/7/130775970/495ded3b3c.pdf
    • http://files.sanctuaryandresistance.org/uploads/1/3/1/3/131398515/vofuwivow-wazojo-sozigikalup-rufaluvevav.pdf
    • https://cdn.shopify.com/s/files/1/0432/6490/1270/files/1138316492.pdf
    • https://cdn.shopify.com/s/files/1/0428/3197/0460/files/golurulogetixo.pdf
    • https://cdn.shopify.com/s/files/1/0432/1204/6491/files/human_fetal_development.pdf
    • https://cdn.shopify.com/s/files/1/0427/8901/1612/files/95066442568.pdf
    • https://cdn.shopify.com/s/files/1/0431/3628/6877/files/69378437192.pdf
    • https://cdn.shopify.com/s/files/1/0438/1887/7090/files/11886538798.pdf
    • https://cdn.shopify.com/s/files/1/0440/8115/2152/files/html_skeleton_code.pdf
    • https://cdn.shopify.com/s/files/1/0430/2694/0067/files/skyscale_lost_guide.pdf
    • https://cdn.shopify.com/s/files/1/0429/1729/8329/files/barefoot_in_the_park_full_script_free.pdf
    • https://cdn.shopify.com/s/files/1/0438/0711/3373/files/adobe_reader_convert_to_word_free_download.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_off0000821c.bin
e1e0157415516140b3649faf30c7b6d4f36473b306357a7698e18288834d9637
pdf-font-stream PDF embedded font (sfnt) at offset 0x821C 5484 bytes
font_01_sfnt_off000094c3.bin
1bad6cbfe3a3de92e77da69c86539ccb62633ef34ab5f2e4a74d698eabee34e7
pdf-font-stream PDF embedded font (sfnt) at offset 0x94C3 10300 bytes