Malicious PDF — malware analysis report

Static analysis result for SHA-256 23f8cb0f60c0592a…

MALICIOUS

PDF

46.9 KB Created: 2020-08-31 07:24:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1c92488dfd5a164ec00f8de51343a99d SHA-1: 286c01ac00176cd4b5193c749dcd7e4313a3c3e2 SHA-256: 23f8cb0f60c0592ab440668ac9c9ccaf2315d705d0d77c94e19cfb445c14d497
152 Risk Score

Malware Insights

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

The PDF file was flagged by multiple critical heuristics indicating malicious redirector links and a link farm. The ML classifier also strongly indicated maliciousness. The document body contains a URL that points to a known malicious redirector, and numerous other links to external PDFs, suggesting a link farm designed to distribute malicious content or engage in SEO abuse. No scripts were extracted from this sample.

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/wix?keyword=gencloben+cream+indications+lumenex
    • https://cdn.shopify.com/s/files/1/0437/2286/6842/files/the_stranger_albert_camus.pdf
    • https://cdn.shopify.com/s/files/1/0435/1344/6564/files/90016543576.pdf
    • https://cdn.shopify.com/s/files/1/0428/9714/6019/files/99072312545.pdf
    • https://cdn.shopify.com/s/files/1/0431/3012/6496/files/viva_la_vida_chords.pdf
    • https://cdn.shopify.com/s/files/1/0430/0275/7281/files/18369154443.pdf
    • https://static.usrfiles.com/ugd/fac845_63f2b21925204f13b1213faa42247a1b.pdf
    • https://static.usrfiles.com/ugd/b8c837_2c9b3ba46b3143a5a3cb622ac9fb4cc7.pdf
    • https://static.usrfiles.com/ugd/7ea8bb_a88ebef3db6b4da9b4bdad3a44de7daa.pdf
    • https://static.usrfiles.com/ugd/6290de_b674d72a9c844072a9d9de271c79ccc6.pdf
    • https://static.usrfiles.com/ugd/b8c837_2e001332d39b4cd69e54935833f64099.pdf
    • https://static.usrfiles.com/ugd/7dd30d_331494eac814467daedd7bbad20e2dfb.pdf
    • https://static.usrfiles.com/ugd/516793_eb9c438832234c30b99335d385227678.pdf
    • https://static.usrfiles.com/ugd/b8c837_1d08ac3d725a4921b691155fbd84b27f.pdf
    • https://static.usrfiles.com/ugd/b8c837_8c79d1e4fec24a21b436b33c2cb6f765.pdf
    • https://static.usrfiles.com/ugd/b8c837_b3e5809652954f9e84b7c3be85fabc93.pdf
    • https://static.usrfiles.com/ugd/b8c837_fdfa90182a5d4bc28e25f13ed5d7ec77.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_off000077a6.bin
ba33257b285b57f38661fbbe56b4b479c9bc0fb1fa9b726ad25add78ae8440eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x77A6 5324 bytes
font_01_sfnt_off000089a5.bin
663f3cf5d42e765a12657dbd74b22ba49ad9039becb904ea67db0249e9abe900
pdf-font-stream PDF embedded font (sfnt) at offset 0x89A5 10716 bytes