Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c90856cbaa7a13b…

MALICIOUS

PDF

41.5 KB Created: 2020-08-04 23:44:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 104c08d465cb153d3fd5d28cd2d99177 SHA-1: 3467cd612c98281bd27c7122f710dc25fa171301 SHA-256: 3c90856cbaa7a13b063b97b4bc60b7bf00e5d30c52730cf0745fa67b6c03e8fe
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, identified as a link farm, with one specifically pointing to known malicious redirector infrastructure. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains a URL that is also present in the embedded link farm, suggesting a coordinated effort to drive traffic to malicious sites. The primary intent appears to be redirecting users to potentially harmful content or further download stages.

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=application+security+architecture+pdf
    • http://suvupaza.arnikafuhrmann.com/uploads/1/3/1/3/131398091/c89384acb6d.pdf
    • http://files.subtek-music.com/uploads/1/3/0/7/130738825/felikanamoxekes.pdf
    • http://files.mdpropertiez.com/uploads/1/3/2/6/132680874/5409574.pdf
    • https://cdn.shopify.com/s/files/1/0433/5537/3720/files/57694829107.pdf
    • https://cdn.shopify.com/s/files/1/0439/0970/9976/files/mulanuwobilaxi.pdf
    • https://cdn.shopify.com/s/files/1/0436/9262/1978/files/convert_ts_to_mp4.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/32600433864.pdf
    • https://cdn.shopify.com/s/files/1/0432/8813/3787/files/the_angle_between_two_vectors.pdf
    • https://cdn.shopify.com/s/files/1/0434/0183/8744/files/7607947038.pdf
    • https://cdn.shopify.com/s/files/1/0431/4241/4493/files/zatilozosusefiturij.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/dosoxuwananeworatimuk.pdf
    • https://cdn.shopify.com/s/files/1/0433/7926/1590/files/kikigo.pdf
    • https://cdn.shopify.com/s/files/1/0430/1104/7575/files/32044957974.pdf
    • https://cdn.shopify.com/s/files/1/0434/6665/3858/files/42216035177.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_off000065f5.bin
95689f5d957a0e3ac155fab23eee9789d623c02c75d05f98bd74f82c355ca771
pdf-font-stream PDF embedded font (sfnt) at offset 0x65F5 5336 bytes
font_01_sfnt_off0000781e.bin
4ed806451fd795e3ad8d352daafcf61f50b98fc4677b511ff2f6d26c66e647e5
pdf-font-stream PDF embedded font (sfnt) at offset 0x781E 9688 bytes