Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d61fe1c5d8922f7…

MALICIOUS

PDF

40.4 KB Created: 2020-08-18 16:28:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f52edb76ef8f8ee19779c026891f5605 SHA-1: b17e46bc0d6a296cc7d8ced03cd89cb2318b7add SHA-256: 9d61fe1c5d8922f7d9c5a9951ff47dd79d8ae7e789597795ae0346874de30ef1
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with the primary link directing to a known malicious redirector. The document body, though heavily obfuscated, contains text related to 'heterogeneous and homogeneous mixtures worksheet answers' and includes the malicious URL, suggesting a lure for educational content that leads to malicious infrastructure. The ML classifier strongly flagged this PDF as malicious.

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=heterogeneous+and+homogeneous+mixtures+worksheet+answers
    • http://sirur.jkashort.com/uploads/1/3/0/8/130874493/dotusobusufezev.pdf
    • https://cdn.shopify.com/s/files/1/0431/2717/7380/files/41746753529.pdf
    • https://cdn.shopify.com/s/files/1/0429/6219/0499/files/64701413331.pdf
    • https://cdn.shopify.com/s/files/1/0437/1329/8581/files/tudakewadujimotevetumet.pdf
    • https://cdn.shopify.com/s/files/1/0439/3231/9912/files/72492171791.pdf
    • https://cdn.shopify.com/s/files/1/0432/5759/4011/files/auto_repair_invoice_form.pdf
    • https://cdn.shopify.com/s/files/1/0433/9662/8641/files/buku_bani_abbasiyah.pdf
    • https://cdn.shopify.com/s/files/1/0427/6187/9719/files/luwipofobarok.pdf
    • https://cdn.shopify.com/s/files/1/0429/7441/2949/files/belajar_pivot_excel_2020.pdf
    • https://cdn.shopify.com/s/files/1/0435/3599/0936/files/mibutigawotugo.pdf
    • https://cdn.shopify.com/s/files/1/0433/1021/9422/files/88237841303.pdf
    • https://cdn.shopify.com/s/files/1/0437/8345/4872/files/55049908146.pdf
    • https://cdn.shopify.com/s/files/1/0429/1287/4662/files/bomugagadalo.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_off00005fa0.bin
5f45498fc4a6645e6cd9abe3f2d8047964e3279f0bf66c3f6d3ba5525248459c
pdf-font-stream PDF embedded font (sfnt) at offset 0x5FA0 5392 bytes
font_01_sfnt_off000071e1.bin
5cd494e7ce6389c0e6e7bffb027d37598b415c10dec3420cb81f1c7fe7ac80a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x71E1 10316 bytes