Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1cb11e216ffc404…

MALICIOUS

PDF

36.1 KB Created: 2020-09-11 01:20:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c54a6223e6b3a5f69aec6895c9031ec0 SHA-1: 4c626430e48bcd7df96dee003af6a9b171090b70 SHA-256: f1cb11e216ffc404676348a9bdb34fea3d5f5d340052a613806573f546251724
152 Risk Score

Malware Insights

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

The PDF contains embedded links, one of which, 'https://ttraff.link/pify?keyword=acorn+stairlift+manual', is flagged as a known malicious redirector. The document body, though heavily obfuscated, contains text suggesting it is a manual for an Acorn stairlift, indicating a social engineering lure. The presence of numerous other links, many pointing to static.usrfiles.com, suggests a link farm or content distribution network used to host the malicious content. 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.link/pify?keyword=acorn+stairlift+manual
    • http://nafomidaf.aivets2018.eu/uploads/1/3/2/8/132814969/0dddc8bd0e6c00.pdf
    • http://files.bradnerbarker.com/uploads/1/3/1/6/131606965/goweva.pdf
    • https://static.usrfiles.com/ugd/b13fd1_eaac788001074e42a5d3142bb0b83ccf.pdf
    • https://static.usrfiles.com/ugd/b8c837_bcd6fcef16a249e19f03c60d404960e0.pdf
    • https://static.usrfiles.com/ugd/c20ea7_95db1c5683ae418ca1fadc7463ff2a90.pdf
    • https://static.usrfiles.com/ugd/575363_5f749c44bdfd4ffd9258daf3b09ceac9.pdf
    • https://static.usrfiles.com/ugd/5438e3_cfeb8b17270c441f8fca77532704d704.pdf
    • https://static.usrfiles.com/ugd/18ee90_22ea2fd15ff24f168a53fec0fca67240.pdf
    • https://static.usrfiles.com/ugd/9374a7_d420f9c1332f448b954d0e24e3175526.pdf
    • https://static.usrfiles.com/ugd/f63f29_cf56d2067a1b425986abe5bdde257c96.pdf
    • https://cdn.shopify.com/s/files/1/0438/2490/6397/files/93151189911.pdf
    • https://cdn.shopify.com/s/files/1/0434/6331/1512/files/74015847913.pdf
    • https://cdn.shopify.com/s/files/1/0428/0962/2687/files/warfarin_guidelines.pdf
    • https://cdn.shopify.com/s/files/1/0430/2805/4169/files/zetik.pdf
    • https://cdn.shopify.com/s/files/1/0434/3293/5574/files/branchement_feux_additionnel_r1200gs.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_off0000513a.bin
5a0a37cddd886464d88566cf3d03edc757b84606a71ea9487b0f1a7b8a13080b
pdf-font-stream PDF embedded font (sfnt) at offset 0x513A 5016 bytes
font_01_sfnt_off00006238.bin
85b0b3b3a3878a44619076d0c4a1548eaba511bd7f30f62a7e657c7f01a7c621
pdf-font-stream PDF embedded font (sfnt) at offset 0x6238 9896 bytes