Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b74d5d1012bafb8…

MALICIOUS

PDF

35.7 KB Created: 2020-08-11 18:29:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f3b2b33bc832f2143ea177b16bd5c5ea SHA-1: 372c10007bbc52270b9c0c0491b7454dcc6b7452 SHA-256: 4b74d5d1012bafb8dbb598afc3616f7232df6bd1f6b7494bd8657aabe47e6747
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one identified as a malicious redirector. The heuristic PDF_SEO_LINK_FARM indicates a large number of external PDF links, suggesting an attempt to manipulate search engine results or distribute malicious content. The ML classifier also strongly flagged this PDF as malicious. The primary attack pattern involves redirecting users through the identified 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.ru/pify?keyword=mathematics+of+finance+questions+and+answers+pdf
    • http://filudilo.fjcampbell.net/uploads/1/3/2/6/132682883/4908549.pdf
    • http://files.sidneyshelbychamber.com/uploads/1/3/1/3/131380469/8edcf51bb33e7f.pdf
    • http://files.augustahbcualumni.com/uploads/1/3/0/7/130775373/9083361.pdf
    • https://cdn.shopify.com/s/files/1/0428/8089/3084/files/dilonogi.pdf
    • https://cdn.shopify.com/s/files/1/0430/0485/4426/files/kalojadesadi.pdf
    • https://cdn.shopify.com/s/files/1/0435/9087/7339/files/bujekokiligetasi.pdf
    • https://cdn.shopify.com/s/files/1/0437/8466/7297/files/deconstruction_architecture.pdf
    • https://cdn.shopify.com/s/files/1/0449/4727/5931/files/angular_js_size.pdf
    • https://cdn.shopify.com/s/files/1/0434/2684/0738/files/somizubuwigajowozirip.pdf
    • https://cdn.shopify.com/s/files/1/0435/4929/4756/files/89695070255.pdf
    • https://cdn.shopify.com/s/files/1/0433/8892/8150/files/72586973269.pdf
    • https://cdn.shopify.com/s/files/1/0431/9356/5342/files/8773528585.pdf
    • https://cdn.shopify.com/s/files/1/0440/6863/4789/files/spanish_to_english_translation_file.pdf
    • https://cdn.shopify.com/s/files/1/0430/0472/3349/files/astm_e8_standards_for_tensile_testing.pdf
    • https://cdn.shopify.com/s/files/1/0446/3493/1363/files/bioreactor_notes.pdf
    • https://cdn.shopify.com/s/files/1/0450/3745/3470/files/subject_verb_agreement_worksheets_grade_3.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_off00004be6.bin
6301ea0dd70d5f42e9642fd16f47b0277843eff72c5b64a1ca80820872893a44
pdf-font-stream PDF embedded font (sfnt) at offset 0x4BE6 5584 bytes
font_01_sfnt_off00005ed2.bin
db1c90f4f0f99f82ac48365fd3093d35267e2fa4aa86f3fafef749aaddab5795
pdf-font-stream PDF embedded font (sfnt) at offset 0x5ED2 10160 bytes