Malicious PDF — malware analysis report

Static analysis result for SHA-256 164f8aeba6db2a82…

MALICIOUS

PDF

42.9 KB Created: 2020-09-05 01:43:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a21387a7f4f4a7aefdca05d9b777d614 SHA-1: db5dba0333c5575f55218b4dc4e91ef151db1e38 SHA-256: 164f8aeba6db2a825ca909a1a0f08ddcb4b3de60c9bf719695059b96810feba9
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm and a primary malicious redirector URL, suggesting a phishing or scam attempt. The document body, though heavily obfuscated, contains the malicious URL and references interview questions, indicating a lure. The presence of embedded URLs and the ML classifier's high confidence score support the malicious verdict.

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.me/wix?keyword=basic+accounting+interview+questions+and+answers+pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0434/6360/6422/files/17071195069.pdf
    • https://cdn.shopify.com/s/files/1/0433/5868/3294/files/47885065382.pdf
    • https://cdn.shopify.com/s/files/1/0429/7926/2615/files/dstv_tv_guide_all_channels.pdf
    • https://cdn.shopify.com/s/files/1/0431/7026/7291/files/36685848097.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/wososopozabe.pdf
    • https://cdn.shopify.com/s/files/1/0430/2841/4618/files/mawazigikesadogabuvo.pdf
    • https://cdn.shopify.com/s/files/1/0431/7865/5903/files/descriptive_comparative_research.pdf
    • https://cdn.shopify.com/s/files/1/0437/8587/9713/files/61177755736.pdf
    • https://cdn.shopify.com/s/files/1/0446/0986/3843/files/echinoderm_theory_of_origin_of_chordates.pdf
    • https://cdn.shopify.com/s/files/1/0438/1881/1552/files/52178306377.pdf
    • https://static.usrfiles.com/ugd/83d902_1fb5298351ec4a1fb42a77f0d39c46a8.pdf
    • https://static.usrfiles.com/ugd/834936_399e6bc9df3a4339b31dcc0868805feb.pdf
    • https://static.usrfiles.com/ugd/2b3f46_0251a25626df474da59233d7f4fc4235.pdf
    • https://static.usrfiles.com/ugd/d4579c_c27ce3a96a7a42f69f979b34f41f74bc.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006874.bin
b4a62c257a9d05bf8d9495927ee7fd7766a5813a5ba98a910bc20a12f65c8c39
pdf-font-stream PDF embedded font (sfnt) at offset 0x6874 5616 bytes
font_01_sfnt_off00007baa.bin
a20d6db85db5d35c1ff6621d58403766c3d9ac36a07aaf92fc5366b527e0bb2d
pdf-font-stream PDF embedded font (sfnt) at offset 0x7BAA 10288 bytes