Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ba7870713d8711f…

MALICIOUS

PDF

77.6 KB Created: 2021-04-27 22:14:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: c182ce44d859becfa8b1e137cd916a45 SHA-1: ca095f97c117bf016bbc7edc22b8996b2cb64bed SHA-256: 4ba7870713d8711f7103c0ca97f80b943fc8180968c3d3ec12bdd5aeee087839
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses an invoice-themed lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://dafemum.ru/strik?utm_term=how+to+fill+out+usps+customs+form PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4369638/normal_604afa9c67856.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475987/normal_603948b24a3dd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386091/normal_603f7db3b7980.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4479904/normal_5ffc76323eb37.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486521/normal_603f15386332d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460457/normal_5ff0632d403bf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415051/normal_605f722518206.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490377/normal_60208f93db387.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4405419/normal_5fe309896c985.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4498883/normal_5fcbc863b2d84.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496381/normal_60416435c4753.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://7e6b698e-d56f-4a21-8c48-787e2f6d39f4.filesusr.com/ugd/7836c9_b0e04896ba134286b8b60373d31cef48.pdf?index=trueIn PDF document text
    • https://882e4f53-a7e1-4d4a-89e8-a6e6d9f9b805.filesusr.com/ugd/9a13d2_642e185db0714c6ab07ea5888b6719b4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c1fe6f80-d45d-4b34-a183-cb70bf2ea01a/18671903595.pdfIn PDF document text
    • https://aa84fbb7-d3ea-4675-94d1-3a2d808898f4.filesusr.com/ugd/661a84_58d0b2d4e56248949a239a0dcd2eb1ce.pdf?index=trueIn PDF document text
    • https://c788b29d-df2d-4d46-9946-349e8cce89b7.filesusr.com/ugd/a9e086_8cd634f9c67a47d28a0b7503858921bc.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0af659e-40c5-4556-84b9-26d39cc1ab82/how_to_replace_liftmaster_garage_door_keypad.pdfIn PDF document text
    • https://e691ad07-92dc-45fa-af10-8929b4045ede.filesusr.com/ugd/87b9a8_5c0f41864d6e4d79b3101e0693ceb194.pdf?index=trueIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FF 5004 bytes
SHA-256: 9c99d3c8927f8b3cbabcf79c4d3c700eef1aa1bae540c62ebc765f27d74f0842
font_01_sfnt_off00010409.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10409 11048 bytes
SHA-256: 64a5015b8813276541e5ea69bfa4db8e8f81a27ce47e6cf4f773bbf0ef0cdc5a