Malicious PDF — malware analysis report

Static analysis result for SHA-256 da9fc16991c34fc8…

MALICIOUS

PDF

32.1 KB Created: 2020-08-16 13:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2123f41ea5dd17a3bd17a42375f6c1a0 SHA-1: ddefb855f46c60ec727ee137ec5c7613f32a9caf SHA-256: da9fc16991c34fc8cca93250def3cf8760c4537dc57811605f6af476ef5ad505
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains a large number of embedded links, with one identified as a malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains the URL https://ttraff.ru/pify?keyword=symmetry+worksheet+ks1+tes, which is flagged as a malicious redirector. The presence of numerous links, including to Shopify domains, suggests an attempt at SEO poisoning or a phishing campaign.

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=symmetry+worksheet+ks1+tes
    • http://biraput.sealsriflescopes.com/uploads/1/3/0/9/130969352/a54a97.pdf
    • http://files.lutzka.com/uploads/1/3/1/0/131069781/bidit-xemojegatopufir-defifexe.pdf
    • http://mavob.thebikery.co.nz/uploads/1/3/0/9/130968996/jefudej-jamezejisad.pdf
    • http://files.a1a-live.com/uploads/1/3/1/8/131871740/2923420.pdf
    • http://files.pointepoa.org/uploads/1/3/0/9/130969301/bapagudaxufibe-wevuvozenejiwe-ginedizuzokaxif-nusomod.pdf
    • https://cdn.shopify.com/s/files/1/0440/0427/8422/files/vubewagojukuritofaru.pdf
    • https://cdn.shopify.com/s/files/1/0431/4575/6833/files/area_of_compound_shapes_worksheet_with_answers.pdf
    • https://cdn.shopify.com/s/files/1/0438/5197/2768/files/xijuzapirokiwupebuzak.pdf
    • https://cdn.shopify.com/s/files/1/0448/9504/3751/files/3d_printing_technology_applications_and_selection.pdf
    • https://cdn.shopify.com/s/files/1/0434/2926/5574/files/9099497559.pdf
    • https://cdn.shopify.com/s/files/1/0429/5173/7498/files/antony_and_cleopatra_critical_analysis.pdf
    • https://cdn.shopify.com/s/files/1/0430/7304/4634/files/16759630943.pdf
    • https://cdn.shopify.com/s/files/1/0439/4916/2654/files/nys_cdl_manual.pdf
    • https://cdn.shopify.com/s/files/1/0436/6965/1606/files/gomapuguzoluxofimeripovup.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_off00004334.bin
ce863ffd57f138c7b5b1b57ed5c96d88fc3f4cd2abeda9739f0b9b5864ec79ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x4334 5096 bytes
font_01_sfnt_off00005482.bin
a6841da16011db526e994803fa91c42ba6e7b2195b81766974ff07326587ef99
pdf-font-stream PDF embedded font (sfnt) at offset 0x5482 9188 bytes