Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb91825e2bda8e71…

MALICIOUS

PDF

52.0 KB Created: 2020-08-25 06:54:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e841ada02cd654a0884c6ef14642272a SHA-1: 6753ffae685b27d67f2670f503a0b90868be70a6 SHA-256: cb91825e2bda8e710fe2c886467e5fa7972408fc21e7d682ce7039480bf19d9b
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1566.002 Spearphishing Link

The PDF was flagged by a critical heuristic for linking to known malicious redirector infrastructure. Additionally, it contains a link farm pointing to multiple PDF files hosted on Shopify, with one URL identified as a potential redirector. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the presence of a malicious redirector URL suggests a phishing or malware delivery attempt.

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=medidas+politicas+de+las+reformas+borbonicas
    • http://bodulixem.psucusa.com/uploads/1/3/1/6/131606490/lokuxujimujujuta.pdf
    • http://files.bethalexlarson.com/uploads/1/3/2/6/132682640/xugib.pdf
    • https://cdn.shopify.com/s/files/1/0433/4338/0631/files/56095696543.pdf
    • https://cdn.shopify.com/s/files/1/0438/6013/2005/files/tomokilexabu.pdf
    • https://cdn.shopify.com/s/files/1/0432/8180/9566/files/arteries_and_veins_anatomy.pdf
    • https://cdn.shopify.com/s/files/1/0457/7371/7670/files/86249867842.pdf
    • https://cdn.shopify.com/s/files/1/0436/6496/5782/files/86033891631.pdf
    • https://cdn.shopify.com/s/files/1/0429/9587/5989/files/nimokezexinofokedozag.pdf
    • https://cdn.shopify.com/s/files/1/0429/0985/9999/files/sedabuxu.pdf
    • https://cdn.shopify.com/s/files/1/0437/8869/7761/files/wowesamoretegugimumuwof.pdf
    • https://cdn.shopify.com/s/files/1/0431/0371/5489/files/zamezofojitafaxeparexena.pdf
    • https://cdn.shopify.com/s/files/1/0433/2670/1718/files/dizuwe.pdf
    • https://cdn.shopify.com/s/files/1/0434/2857/7447/files/anarchism_and_other_essays_emma_goldman.pdf
    • https://cdn.shopify.com/s/files/1/0434/1622/3906/files/a._p._r_full_form.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/
    • https://cdn.shopify.com/s/files/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00008992.bin
5923f3fa33df4ae7e3957a876ce1d2f5ce1175e263cf9cc3980d0010191cbb71
pdf-font-stream PDF embedded font (sfnt) at offset 0x8992 5448 bytes
font_01_sfnt_off00009c00.bin
9e36722a6def29f3d4e68b8eea5e6a4b0557fec91ce379909a285129b43d08ed
pdf-font-stream PDF embedded font (sfnt) at offset 0x9C00 11344 bytes