Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81d3a82ee44591d…

MALICIOUS

PDF

43.1 KB Created: 2020-08-29 10:58:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ea7608d3e6ef210d447efc994b8c1b8d SHA-1: d867802da4168c673e130431479edd272c707089 SHA-256: a81d3a82ee44591d6f486357eddeadd0151bcf995f914a2f58edb8d5c5c9eb83
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one specifically pointing to a known malicious redirector. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass external PDF link farm, suggesting the document's primary purpose is to host these links. The ML classifier also strongly flagged this PDF as malicious. The document body itself is heavily obfuscated and contains the malicious URL.

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/wix?keyword=victoria+lomba+santander
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/25668779603.pdf
    • https://cdn.shopify.com/s/files/1/0433/8896/0919/files/97243804092.pdf
    • https://cdn.shopify.com/s/files/1/0448/2826/2560/files/sakurai_modern_quantum_mechanics_solutions.pdf
    • https://static.usrfiles.com/ugd/b8c837_bbc68f1b29804bc09ad3a108ee8fc692.pdf
    • https://static.usrfiles.com/ugd/b8c837_c5fbf3bea70c4740b453ff6dc1dc224e.pdf
    • https://static.usrfiles.com/ugd/b8c837_ebf02657339b4e02872284978779b162.pdf
    • https://static.usrfiles.com/ugd/b8c837_dc7aa24064ba448a99e040353308ca38.pdf
    • https://cdn.shopify.com/s/files/1/0434/5387/4329/files/autobiography_of_a_coin_for_class_11.pdf
    • https://cdn.shopify.com/s/files/1/0432/6604/8165/files/59329429704.pdf
    • https://cdn.shopify.com/s/files/1/0434/8536/4390/files/jupomotatefinolikug.pdf
    • https://cdn.shopify.com/s/files/1/0434/2376/0536/files/memuvudotabi.pdf
    • https://cdn.shopify.com/s/files/1/0428/1463/6198/files/rodozun.pdf
    • https://cdn.shopify.com/s/files/1/0433/4757/4949/files/pejakazinad.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/zorugeligix.pdf
    • https://cdn.shopify.com/s/files/1/0463/0754/1149/files/98149101786.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005f1d.bin
ce0532a629288b3a137abee247bce795f2c3c3747252cf893a867bec0cfd6ef1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F1D 5192 bytes
font_01_sfnt_off00007093.bin
614ed29908490b2cf6eaaca9d0091e1e84029f876ebc83a1b5e4ffadee7cd41d
pdf-font-stream PDF embedded font (sfnt) at offset 0x7093 1864 bytes
font_02_sfnt_off000079a1.bin
6245e063200470e9030ac483db5e533d3d9e1b6c8e2ae737085dd9d1618ec320
pdf-font-stream PDF embedded font (sfnt) at offset 0x79A1 11192 bytes