Malicious PDF — malware analysis report

Static analysis result for SHA-256 83d18035dbd207b4…

MALICIOUS

PDF

54.1 KB Created: 2020-08-19 03:19:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c9a6139b804a3704bfbc429a0536abc8 SHA-1: 256f41b34a9653f28dd5cef98e3aaf67e0f40c4c SHA-256: 83d18035dbd207b458b703983d1deedec4f4d31b970b06959d28459fac4bc499
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link to a known malicious redirector, ttraff.cc, which is disguised as a 'letter of interest template teacher'. The ML classifier strongly indicates maliciousness. The document body, though heavily obfuscated, contains the same malicious URL, reinforcing the lure. The presence of numerous external PDF links, many hosted on Shopify, suggests a link farm or SEO poisoning attempt to distribute the malicious content.

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.cc/pify?keyword=letter+of+interest+template+teacher
    • http://files.stylecounselatl.com/uploads/1/3/1/4/131483337/b708e42646.pdf
    • http://xixosejuz.montaukbeachbungalow.com/uploads/1/3/0/9/130969016/mofajunarumokix-funememep.pdf
    • http://files.alfredartwalk.org/uploads/1/3/0/9/130969873/cc1c10af448f.pdf
    • http://files.herovision.ca/uploads/1/3/1/4/131453620/gitamu-vatakuderiziv-puxegejepomawo.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/46552055365.pdf
    • https://cdn.shopify.com/s/files/1/0439/7318/1598/files/25565636489.pdf
    • https://cdn.shopify.com/s/files/1/0446/3493/1363/files/boulevard_of_broken_dreams_drum_tab.pdf
    • https://cdn.shopify.com/s/files/1/0436/2564/4192/files/wedituvugifi.pdf
    • https://cdn.shopify.com/s/files/1/0432/9340/9438/files/fuviteposidifuxesazujoz.pdf
    • https://cdn.shopify.com/s/files/1/0440/8197/1365/files/80348970299.pdf
    • https://cdn.shopify.com/s/files/1/0431/0640/2453/files/77807424429.pdf
    • https://cdn.shopify.com/s/files/1/0435/6934/8763/files/bacterias_gram_positivas_y_gram_negativas.pdf
    • https://cdn.shopify.com/s/files/1/0431/0905/6668/files/piroterik.pdf
    • https://cdn.shopify.com/s/files/1/0429/6045/3791/files/nuxuvixadedotod.pdf
    • https://cdn.shopify.com/s/files/1/0430/9726/0192/files/2319510953.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kufanagapaxo.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_off000094d9.bin
e376869a2aa3c96a7761c1a714fdc7a4223c61c63e2181e36c83a6dbe90729dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x94D9 5196 bytes
font_01_sfnt_off0000a65a.bin
f345d27018774a7041fac9da2f5c4816f70c50647dec53014c56d5cf57fdfa35
pdf-font-stream PDF embedded font (sfnt) at offset 0xA65A 10788 bytes