Malicious PDF — malware analysis report

Static analysis result for SHA-256 9734f349496086cc…

MALICIOUS

PDF

45.0 KB Created: 2020-09-01 11:11:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cf061aa3e87d67fd4feeed4ad76ad005 SHA-1: 6f8a44f015bb5ee1e31392edb8c28cd450d0d689 SHA-256: 9734f349496086cc539f2db396688cd4878f0527dd7b8886b3fb7ebfe2304252
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.001 Malicious Link

The PDF contains a prominent link that redirects to a known malicious domain, disguised as free online aptitude test practice. The ML classifier strongly indicated maliciousness, and the PDF structure includes a large number of external links, suggesting a link farm or redirection strategy. The document body, though heavily obfuscated, contains the same lure text and the malicious URL.

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=free+online+aptitude+test+practice+with+answers
    • https://static.usrfiles.com/ugd/576447_8f4c7b34c8db40d2b003dd770e15daca.pdf
    • https://static.usrfiles.com/ugd/1c8c6c_3f726b27b0db4203a8a313bb71c75ac4.pdf
    • https://static.usrfiles.com/ugd/b8c837_1089c6a8614948b79ff195f8fdd50e4e.pdf
    • https://static.usrfiles.com/ugd/b8c837_d8353d9a4b014656bbdf633219a8d520.pdf
    • https://static.usrfiles.com/ugd/05900a_3cdb0109bf2b4ee081c8fc3201033d57.pdf
    • https://static.usrfiles.com/ugd/88a84f_f2f4b1dad8a54b2abd056d4165dd2ad5.pdf
    • https://cdn.shopify.com/s/files/1/0463/0698/4098/files/50448444758.pdf
    • https://cdn.shopify.com/s/files/1/0433/7244/5854/files/fodojolipadulufexi.pdf
    • https://cdn.shopify.com/s/files/1/0434/6062/4537/files/35109462357.pdf
    • https://cdn.shopify.com/s/files/1/0439/0413/9416/files/vapivosobiwobazagapane.pdf
    • https://cdn.shopify.com/s/files/1/0437/7473/8581/files/bofodiwuwubepufatituvu.pdf
    • https://cdn.shopify.com/s/files/1/0435/0056/8736/files/nukovinijadujotonoradezob.pdf
    • https://cdn.shopify.com/s/files/1/0428/6867/0620/files/27205639300.pdf
    • https://cdn.shopify.com/s/files/1/0434/2795/4853/files/69193884839.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_off00007150.bin
0041426ca4bc1c95e7eaca9c022854887955fbbb3c06ba99335906fbedf51a85
pdf-font-stream PDF embedded font (sfnt) at offset 0x7150 5208 bytes
font_01_sfnt_off00008313.bin
8041903d4bed3359f36cf5210c74a96fb681617ff5b4862f89dd6d6988245869
pdf-font-stream PDF embedded font (sfnt) at offset 0x8313 10416 bytes