Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9d7e1ab2bbc7067…

MALICIOUS

PDF

35.9 KB Created: 2020-08-29 22:13:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f1d6541426da9f3f1b91e6ff4b6faf32 SHA-1: f8993363740d3da64ac800f6bf3a0e19486277b4 SHA-256: a9d7e1ab2bbc7067ac6291fd819bd7de468da2199a077dc6609d29681350bc07
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, which is also present in the document body. The file also exhibits characteristics of a PDF link farm, suggesting an attempt to distribute malicious content. The ML classifier strongly indicates maliciousness. The primary attack vector appears to be luring users to a malicious URL disguised as a book download.

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/wix?keyword=nivaldo+tro+chemistry+a+molecular+approach+3rd+edition
    • https://static.usrfiles.com/ugd/b8c837_aa8fbb4b95394160820bdbedba2ec3fe.pdf
    • https://static.usrfiles.com/ugd/b8c837_de84b0372ee94273bc50965e0f4c71ee.pdf
    • https://static.usrfiles.com/ugd/277b62_716527e2f5cf47329d35c674c52734ac.pdf
    • https://static.usrfiles.com/ugd/b8c837_132eb013f89043e59db09a7000f93195.pdf
    • https://cdn.shopify.com/s/files/1/0430/9896/4117/files/rufazuranoxibab.pdf
    • https://cdn.shopify.com/s/files/1/0432/9468/7400/files/big_ideas_math_high_school_algebra_1.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/87967576867.pdf
    • https://cdn.shopify.com/s/files/1/0433/2145/8853/files/ratiguzaridiwiwekev.pdf
    • https://static.usrfiles.com/ugd/b8c837_2c72998f81a24045ab070bbb986368ff.pdf
    • https://static.usrfiles.com/ugd/b8c837_e92078842fa141ccbf09640afcee7c59.pdf
    • https://static.usrfiles.com/ugd/b8c837_923bbfc14b07433fbd2d5976e3bd228b.pdf
    • https://cdn.shopify.com/s/files/1/0436/0850/6531/files/ruzifilaguna.pdf
    • https://cdn.shopify.com/s/files/1/0430/4686/3005/files/nijunorerilobebufi.pdf
    • https://cdn.shopify.com/s/files/1/0433/8515/9843/files/wufinotabunazakab.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_off00004e80.bin
e87e4415a09312b62e3bd095dc22ed6c64bcc1e9ae3d5259ce9c46fec9eebf60
pdf-font-stream PDF embedded font (sfnt) at offset 0x4E80 5608 bytes
font_01_sfnt_off00006177.bin
16272913226a360f93050f9ca0e123c7518fde4405f0d470afe819bf850eb9e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x6177 9632 bytes