Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7ba6f65b8f9f5a5…

MALICIOUS

PDF

77.8 KB Created: 2021-05-30 07:46:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4f36f963f727b989a4680b4bd4343226 SHA-1: e293f6874abf9a987fa5df5a85f0d0fc70d6f0dc SHA-256: c7ba6f65b8f9f5a5e4da250d32171039198e63f85c1dd67913913485b1bce2cb
136 Risk Score

Malware Insights

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

The sample is a PDF document flagged by ML classifiers as malicious and exhibiting characteristics of an advance-fee scam. It contains numerous external links, with one pointing to 'jacksth.ru', suggesting an attempt to redirect the user to a malicious site. The document body, though heavily obfuscated, combined with the heuristic 'SE_ADVANCE_FEE_SCAM_LURE', indicates a phishing or fraud attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • Advance-fee lottery/parcel scam lure high SE_ADVANCE_FEE_SCAM_LURE
    Document contains lottery/beneficiary or prize language together with large-value draft/funds wording and parcel/courier delivery requirements. This is a classic advance-fee fraud document shape.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://jacksth.ru/123?utm_term=fannie+mae+multifamily+dus+guide
    • https://cdn-cms.f-static.net/uploads/4421471/normal_604b38e7e2a5f.pdf
    • https://cdn-cms.f-static.net/uploads/4490263/normal_5fe825d513070.pdf
    • https://static.s123-cdn-static.com/uploads/4392864/normal_5ffe73200a45d.pdf
    • https://miluxeto.weebly.com/uploads/1/3/5/3/135326788/wegovibip_narunavijugen_namajosaduzevor.pdf
    • https://cdn-cms.f-static.net/uploads/4471946/normal_601f952279c45.pdf
    • https://fogepiwutakeru.weebly.com/uploads/1/3/2/3/132302718/gexebor.pdf
    • https://cdn-cms.f-static.net/uploads/4473375/normal_5fe83c28ec884.pdf
    • https://static.s123-cdn-static.com/uploads/4459034/normal_5fe3a4984b173.pdf
    • https://panulozeti.weebly.com/uploads/1/3/5/3/135351273/16881.pdf
    • https://metubunotawe.weebly.com/uploads/1/3/4/5/134595280/rufebiredokovotanez.pdf
    • https://cdn-cms.f-static.net/uploads/4376856/normal_5fd7c9b2e84bf.pdf
    • https://modezajuv.weebly.com/uploads/1/3/4/0/134097040/2800784.pdf
    • https://zopigokarage.weebly.com/uploads/1/3/4/3/134346298/9ae75a2feee5.pdf
    • https://faniwavuguvupos.weebly.com/uploads/1/3/4/4/134478403/7cec86d52.pdf
    • https://tozubovudifudi.weebly.com/uploads/1/3/5/9/135973827/nadusifene.pdf
    • https://static.s123-cdn-static-d.com/uploads/4422914/normal_60b041c610d2e.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/b6630ec9-1552-4288-9bdd-90c5aa9ec987/how_to_install_google_maps_on_iphone_7.pdf
    • https://uploads.strikinglycdn.com/files/c246bc0a-1d57-4293-9c43-c3751c93266a/5131567204.pdf
    • https://uploads.strikinglycdn.com/files/4b9327e6-1f82-429e-a4d9-f9f165a9d447/pafajofusi.pdf
    • https://uploads.strikinglycdn.com/files/a047b5a7-42e9-4668-b431-29b786b51ce3/el_amor_en_los_tiempos_del_colera_pelicula_descargar.pdf
    • https://uploads.strikinglycdn.com/files/964af0cf-a702-4000-bf17-c43559f13d85/how_to_end_a_restaurant_review_essay.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f27e.bin
a785f8173657be2f77cb57f0ed55b95d9ecb3c1b7f5ebf517e736e277836f415
pdf-font-stream PDF embedded font (sfnt) at offset 0xF27E 5188 bytes
font_01_sfnt_off0001042b.bin
38f45d737a6054d92490ca04a5c7f7298bc4b96e54d0f6e10c7498825f854c22
pdf-font-stream PDF embedded font (sfnt) at offset 0x1042B 11156 bytes