Malicious PDF — malware analysis report

Static analysis result for SHA-256 c578eca769d9c370…

MALICIOUS

PDF

40.6 KB Created: 2020-09-04 10:01:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cdc7811694655122c50e95c0ff9dc8ec SHA-1: d6cf045cb54d9bb87eade29192750663228668e6 SHA-256: c578eca769d9c370c7e5a992cc0b9aeb08e6d2e91ad832ed1e107b0987bb5566
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, which is also present in the document body. This link, 'https://ttraff.me/wix?keyword=learn+to+speak+english+free+worksheets', is presented as a lure for free English worksheets, aiming to trick users into clicking it. The PDF also contains a large number of embedded links, many pointing to Shopify domains, suggesting a link farm or SEO manipulation tactic. The ML classifier strongly supports the malicious nature of this PDF.

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=learn+to+speak+english+free+worksheets
    • https://cdn.shopify.com/s/files/1/0460/3694/3007/files/manual_of_antimicrobial_susceptibility_testing.pdf
    • https://cdn.shopify.com/s/files/1/0439/4015/1454/files/87248195622.pdf
    • https://cdn.shopify.com/s/files/1/0432/8361/1801/files/40164537768.pdf
    • https://cdn.shopify.com/s/files/1/0431/6259/9584/files/6153469365.pdf
    • https://cdn.shopify.com/s/files/1/0432/4294/6715/files/55407877455.pdf
    • https://cdn.shopify.com/s/files/1/0434/6976/6808/files/lolebemopegijixedaben.pdf
    • https://static.usrfiles.com/ugd/4329d7_4863eacac74645b89a4b25553bff2b5e.pdf
    • https://static.usrfiles.com/ugd/b8c837_38b229dc1e31431aaf3ada771b33d3cc.pdf
    • https://static.usrfiles.com/ugd/e33828_bdfadbbc42de45b39d3d91c98f8db17d.pdf
    • https://static.usrfiles.com/ugd/06497e_1b84964e514d4679ae58c4fe64ba2a98.pdf
    • https://static.usrfiles.com/ugd/df4650_c31648850e9a4e23831b75093a3b88f9.pdf
    • https://static.usrfiles.com/ugd/4d6844_7547f133c24e428e85f3daadb3fa9159.pdf
    • https://static.usrfiles.com/ugd/625844_24858c255ead4cbc93ce0a12922eca1d.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_off000060d5.bin
431142694419e1699544c637cacd075d9663a227f6d6164030454e1e96058784
pdf-font-stream PDF embedded font (sfnt) at offset 0x60D5 5260 bytes
font_01_sfnt_off000072cf.bin
e274a8dbe4f8467e4eaeab1cf080ac14f99ba6ee2ede32cce4f70de5ef409040
pdf-font-stream PDF embedded font (sfnt) at offset 0x72CF 10120 bytes