Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5eafe49d2eece46…

MALICIOUS

PDF

46.4 KB Created: 2020-08-08 04:39:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 26149fbd909ffc371e63848b07eb38ce SHA-1: 122db6281a2151d142c4299a22b0697420910c33 SHA-256: a5eafe49d2eece46fdedcd2d9988a2262f40a8004bdba3c9f83c8c280b4f173b
154 Risk Score

Malware Insights

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

The PDF contains a high number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector. The document body, though heavily obfuscated, contains the text 'Ap biology textbook online pdf' and the malicious URL, suggesting a lure to trick users into clicking the link. The ML classifier also strongly indicated maliciousness.

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=ap+biology+textbook+online+pdf
    • http://rukuxanu.amazingdownunder.com/uploads/1/3/1/4/131453574/luderim.pdf
    • http://zekeso.alex-andonov.com/uploads/1/3/1/3/131383791/ba00eb70d.pdf
    • http://files.ewhurstbowls.co.uk/uploads/1/3/1/4/131454352/a13741fb4101fbc.pdf
    • http://files.indiepeacock.com/uploads/1/3/1/3/131380456/majok_vilidurafadu_latadumoger_pededikefa.pdf
    • https://cdn.shopify.com/s/files/1/0432/7433/8454/files/fujamoni.pdf
    • https://cdn.shopify.com/s/files/1/0428/2286/0966/files/nerononitu.pdf
    • https://cdn.shopify.com/s/files/1/0437/2057/3082/files/optimal_binary_search_tree_algorithm.pdf
    • https://cdn.shopify.com/s/files/1/0449/6248/0296/files/sony_bdp-_s3500_manual.pdf
    • https://cdn.shopify.com/s/files/1/0432/9242/6405/files/nufuwetaviramun.pdf
    • https://cdn.shopify.com/s/files/1/0429/6821/9799/files/lowe_s_business_account.pdf
    • https://cdn.shopify.com/s/files/1/0434/5410/3713/files/kusokozinujapodu.pdf
    • https://cdn.shopify.com/s/files/1/0428/8380/9439/files/27818578559.pdf
    • https://cdn.shopify.com/s/files/1/0437/2201/4870/files/lavamotilub.pdf
    • https://cdn.shopify.com/s/files/1/0437/3980/7893/files/bexomofawopamijil.pdf
    • https://cdn.shopify.com/s/files/1/0428/2921/7958/files/697465958.pdf
    • https://cdn.shopify.com/s/files/1/0436/6611/2662/files/73302274686.pdf
    • https://cdn.shopify.com/s/files/1/0430/7507/6258/files/tubepezafamuzukave.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_off00007665.bin
1d9e4e90d823bb41d54d3853d5545176e48dd646e0c7e44d42e686daa029b752
pdf-font-stream PDF embedded font (sfnt) at offset 0x7665 5088 bytes
font_01_sfnt_off000087de.bin
021376923dd7561b045a6145aac7df036cab6ab4b895a6d5050faa2e299f4701
pdf-font-stream PDF embedded font (sfnt) at offset 0x87DE 11088 bytes