Malicious PDF — malware analysis report

Static analysis result for SHA-256 819bc5e6d44399af…

MALICIOUS

PDF

32.4 KB Created: 2020-09-01 05:45:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0d73dc02bde0f39bb07c9b9dd2be46b0 SHA-1: 7e7ee75071d24699c4a8734e03a85d686605501e SHA-256: 819bc5e6d44399af8000ad1514b0f32c64f1be161497228813cbd0b523342e13
154 Risk Score

Malware Insights

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

The PDF document contains embedded links that redirect to a malicious URL, identified as a redirector. The document body, though heavily obfuscated, suggests a lure related to educational materials ('pre-algebra worksheet'). The presence of numerous external PDF links, many pointing to Shopify, indicates a link farm strategy, likely to improve SEO for malicious content or to distribute further payloads. The ML classifier strongly flagged this PDF as malicious.

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=pre-+algebra+worksheet+u4-+1+answers
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0431/3009/3728/files/20503965487.pdf
    • https://cdn.shopify.com/s/files/1/0438/9116/3291/files/10632782750.pdf
    • https://cdn.shopify.com/s/files/1/0428/8797/0975/files/kukixuxobamutawamiguwizuz.pdf
    • https://cdn.shopify.com/s/files/1/0438/5121/9104/files/bobo_live_88_tv_apk.pdf
    • https://static.usrfiles.com/ugd/3fc21f_9600e419838b47cfb6715f0862f5ccaf.pdf
    • https://static.usrfiles.com/ugd/69b86f_2a344e30661244bf8ba32a4b525f227f.pdf
    • https://static.usrfiles.com/ugd/ae15ca_8f880106585444c4b1f43061aadd4ea8.pdf
    • https://static.usrfiles.com/ugd/f63f29_7d90bb26363e477eb172d7da06b14d39.pdf
    • https://static.usrfiles.com/ugd/191a6d_7fac626b162d4afb854f58a1d4efe7ba.pdf
    • https://static.usrfiles.com/ugd/64d889_2e7f75bf7a47485faf63707d6b9522f7.pdf
    • https://cdn.shopify.com/s/files/1/0437/6202/4605/files/gemedunavub.pdf
    • https://cdn.shopify.com/s/files/1/0435/7373/9675/files/4889967635.pdf
    • https://cdn.shopify.com/s/files/1/0437/9272/8226/files/fekoviwe.pdf
    • https://cdn.shopify.com/s/files/1/0431/6584/3620/files/archaeologies_of_sexuality.pdf
    • https://cdn.shopify.com/s/files/1/0432/1126/0062/files/49475559440.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_off0000440f.bin
0f33d39b5bb9b652f2b31b239e9a7aa0df746c480d832badd82f575b590ee875
pdf-font-stream PDF embedded font (sfnt) at offset 0x440F 5416 bytes
font_01_sfnt_off0000569a.bin
beffbd0ac035b08bf257b73d083ce2bf2953b1706472a2357f1c8e9572348409
pdf-font-stream PDF embedded font (sfnt) at offset 0x569A 8896 bytes