Malicious PDF — malware analysis report

Static analysis result for SHA-256 78d721a1e2a1ee47…

MALICIOUS

PDF

33.5 KB Created: 2020-08-29 23:21:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 125836665892bec3b5cd12b75ed95250 SHA-1: 349c3c0bf314cf70990c55be3469f3453de3b1e4 SHA-256: 78d721a1e2a1ee473f2935aa708547df7a26f535bc8cd6b796aa038d14342d51
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a critical heuristic firing for linking to known malicious redirector infrastructure, specifically a URL related to 'animal farm study guide answer key'. This URL is presented within the document body, suggesting a social engineering lure. The presence of numerous other links, many pointing to benign Shopify domains, indicates a link farm strategy, likely to obscure the malicious redirector. The ML classifier also strongly flagged this PDF as malicious.

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/wix?keyword=animal+farm+study+guide+answer+key
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0436/6663/6953/files/vegalumemewomegobejufaxa.pdf
    • https://cdn.shopify.com/s/files/1/0465/0965/4174/files/ignou_assignment_submission_front_page.pdf
    • https://cdn.shopify.com/s/files/1/0438/7382/9032/files/knapsack_problem_dynamic_programming.pdf
    • https://cdn.shopify.com/s/files/1/0431/7285/5967/files/voltmeter_ammeter_method.pdf
    • https://cdn.shopify.com/s/files/1/0432/3953/8851/files/99735347105.pdf
    • https://static.usrfiles.com/ugd/b8c837_c4988329c7404ffa87ceea3411f0b592.pdf
    • https://static.usrfiles.com/ugd/b8c837_070ce2bf6836403db4bed0a752beced0.pdf
    • https://static.usrfiles.com/ugd/b8c837_a070c81b71a24ae6b21dd10e15ed75aa.pdf
    • https://static.usrfiles.com/ugd/7ff653_27f99c01a0e743e995d640510cdde55d.pdf
    • https://cdn.shopify.com/s/files/1/0433/9453/1493/files/mopinone.pdf
    • https://cdn.shopify.com/s/files/1/0435/5915/7921/files/lujosukupovavadudex.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000044f1.bin
299ee29449762a00194cc27ada37242abdf948bd28f1cbf66dfe38f481e62712
pdf-font-stream PDF embedded font (sfnt) at offset 0x44F1 5472 bytes
font_01_sfnt_off00005782.bin
e793c1c46a34f1c37801a9fe859475e03812e14fe4aa825ec9a1a1b8989976e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x5782 10044 bytes