Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b107c9357f79cb6…

MALICIOUS

PDF

42.7 KB Created: 2020-08-15 05:13:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f2ffd2c740a8398c97f5d8c13ac50bed SHA-1: d5d60d9a28f0651b8d4635a3f7073606145a7c0a SHA-256: 5b107c9357f79cb6c417c001b208f70c27e195af87e31d2bcc04cad288e1d22b
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, including one to a known malicious redirector, disguised as free worksheets. This technique, combined with the ML classifier's high confidence, indicates a malicious intent to redirect users to harmful sites. The presence of a link farm suggests an attempt to obscure the malicious destination and potentially for SEO manipulation.

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=free+worksheets+possessive+nouns
    • http://files.stfrancesbasketball.com/uploads/1/3/0/7/130775102/3353682.pdf
    • http://kigalep.jacquelyncarterdesigns.com/uploads/1/3/1/6/131637136/kivorogo.pdf
    • http://files.soaringhawkvineyards.com/uploads/1/3/0/7/130775633/kalitetuwipe.pdf
    • http://files.prodigyracingassociation.com/uploads/1/3/2/6/132681969/zezefi.pdf
    • http://files.antlerspecialtygoods.com/uploads/1/3/1/4/131437306/wunog.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0429/3813/8783/files/7967170765.pdf
    • https://cdn.shopify.com/s/files/1/0440/2970/6390/files/timothy_keller_counterfeit_gods.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/38967404473.pdf
    • https://cdn.shopify.com/s/files/1/0430/4030/9402/files/daxurenuxuz.pdf
    • https://cdn.shopify.com/s/files/1/0430/9480/2581/files/58621221523.pdf
    • https://cdn.shopify.com/s/files/1/0436/7453/4041/files/absolute_value_graphing_worksheet.pdf
    • https://cdn.shopify.com/s/files/1/0433/5940/4197/files/suzigojabavuwexewipamag.pdf
    • https://cdn.shopify.com/s/files/1/0428/5058/2684/files/20358974742.pdf
    • https://cdn.shopify.com/s/files/1/0428/8672/5795/files/5639983387.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_off000069e9.bin
3ba43c8d9e877ccb522a9f292a8ac2c8d59eb797e6bbf2503f3cfbc8f90df819
pdf-font-stream PDF embedded font (sfnt) at offset 0x69E9 4836 bytes
font_01_sfnt_off00007a74.bin
fa84ef502bf3f6fa1eeb17952dbc610415eb820aa198e580c2cb2a2c34849010
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A74 10456 bytes