Malicious PDF — malware analysis report

Static analysis result for SHA-256 cacc771d088dc2e5…

MALICIOUS

PDF

39.4 KB Created: 2020-08-12 16:01:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 08691bd566079db372b0472c61a82f03 SHA-1: 74e005c60d9a46fbcb5a1694bcc834dbc58676f4 SHA-256: cacc771d088dc2e59f28ee1c5f4ee37b4e4c0227636ad3a222c1977dd181dbfd
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, many of which point to a link farm hosted on Shopify, and at least one link directs to a known malicious redirector. The ML classifier strongly indicates maliciousness. The primary attack vector appears to be SEO poisoning, where users searching for specific PDF topics are led to these malicious links.

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/pify?keyword=accounting+system+design+pdf
    • http://files.countrysongfarm.com/uploads/1/3/0/8/130814769/b5b0b005a8.pdf
    • http://zirujuw.mdp.gallery/uploads/1/3/1/1/131164250/2858c4bd70862.pdf
    • http://files.theatelierllc.com/uploads/1/3/0/7/130775707/gotugilurewosinak.pdf
    • https://cdn.shopify.com/s/files/1/0430/0151/2090/files/jusimumeboranepinikativo.pdf
    • https://cdn.shopify.com/s/files/1/0430/8375/9765/files/whats_a_webhook_discord.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/53262414385.pdf
    • https://cdn.shopify.com/s/files/1/0434/7405/9424/files/bidunodunurezugixefuvite.pdf
    • https://cdn.shopify.com/s/files/1/0427/4136/6951/files/podelapebaruj.pdf
    • https://cdn.shopify.com/s/files/1/0437/9272/8226/files/5726149581.pdf
    • https://cdn.shopify.com/s/files/1/0432/4173/4311/files/vudalarufapekaromovud.pdf
    • https://cdn.shopify.com/s/files/1/0432/0375/6191/files/25864932567.pdf
    • https://cdn.shopify.com/s/files/1/0428/9583/5295/files/ansys_icem_cfd_tutorial.pdf
    • https://cdn.shopify.com/s/files/1/0434/2684/0737/files/jikafarevogija.pdf
    • https://cdn.shopify.com/s/files/1/0435/4503/4911/files/reddit_r_hearthstone.pdf
    • https://cdn.shopify.com/s/files/1/0428/7044/0095/files/35292006609.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_off00005e60.bin
3a3bbb360d9ed1e66feb8ca97a02807efae1bfeb2910f28259e88e13d7c477e3
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E60 5228 bytes
font_01_sfnt_off0000702a.bin
4441740a78676eb4963607217398d7e71ef37d8a9ed73c42d4fe3f340a0e6b30
pdf-font-stream PDF embedded font (sfnt) at offset 0x702A 9564 bytes