Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6962e5b4d2aeb97…

MALICIOUS

PDF

39.6 KB Created: 2020-08-02 14:59:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 221efc1b51a9959f7f35987ab16e777a SHA-1: 4fe851657167f6f4d44215bab86a36fc4f8fcee1 SHA-256: f6962e5b4d2aeb97621a9e6cd5a43db9db5b54387986c688b5b732e86d74bf9d
154 Risk Score

Malware Insights

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

The PDF document was flagged by multiple critical heuristics for containing malicious redirector links and a large number of external links, suggesting a link farm. The ML classifier also strongly indicated maliciousness. The primary malicious IOC is the redirector URL, which likely leads to further malicious content. The document body contains obfuscated text and a reference to the redirector URL, reinforcing the malicious intent.

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=easter+event+osrs
    • http://files.lambsbride.org/uploads/1/3/0/8/130874139/51740bc5b324c.pdf
    • http://files.fourthfeathers.co.uk/uploads/1/3/0/9/130969768/fiwuzudos_worujuxabesutop_nijijinir.pdf
    • http://files.spiraldancinglife.org/uploads/1/3/0/8/130814855/2579857.pdf
    • https://cdn.shopify.com/s/files/1/0429/1769/1559/files/golang_http_get.pdf
    • https://cdn.shopify.com/s/files/1/0430/5597/2506/files/stewart_james_calculus_7e.pdf
    • https://cdn.shopify.com/s/files/1/0429/2070/6204/files/28046195002.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/63912397784.pdf
    • https://cdn.shopify.com/s/files/1/0431/6980/8535/files/94293538557.pdf
    • https://cdn.shopify.com/s/files/1/0431/6479/5044/files/66706563023.pdf
    • https://cdn.shopify.com/s/files/1/0430/1763/3945/files/xititibixikufiwa.pdf
    • https://cdn.shopify.com/s/files/1/0435/5971/4971/files/xakejil.pdf
    • https://cdn.shopify.com/s/files/1/0435/6951/2607/files/kms_urban_dictionary.pdf
    • https://cdn.shopify.com/s/files/1/0437/7047/8746/files/57799749823.pdf
    • https://cdn.shopify.com/s/files/1/0433/8778/1276/files/11434461227.pdf
    • https://cdn.shopify.com/s/files/1/0429/4334/8892/files/76085492956.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_off0000604a.bin
6146ad5bbfd3775924c22cec8f70bce354b6437407a57c20bedbc8c8cc53434f
pdf-font-stream PDF embedded font (sfnt) at offset 0x604A 4664 bytes
font_01_sfnt_off00007036.bin
8f292a3e191f795d1a3c842cc9eb146738cb82955d3dea4c7f53109fdc8e7ec8
pdf-font-stream PDF embedded font (sfnt) at offset 0x7036 9872 bytes