Malicious PDF — malware analysis report

Static analysis result for SHA-256 48883b635d7a9483…

MALICIOUS

PDF

81.1 KB Created: 2021-05-01 09:44:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: ef8c3393ac9bd43833ff1df934eedaa1 SHA-1: 581fb27966a6633368561dc223b6c94df36c39d3 SHA-256: 48883b635d7a94838928331845190a82d7ad5e1aebc31766245e0678a36a3a14
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded links pointing to various websites, many of which are hosted on disposable domains, indicating a link farm designed to redirect users to malicious infrastructure. The heuristic firings confirm the presence of malicious redirector links and a link farm on disposable hosting. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • 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.
  • 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://crophysi.ru/strik?utm_term=how+to+get+over+childhood+emotional+neglect In PDF document text
    • https://koxamuru.weebly.com/uploads/1/3/4/8/134890845/7667111.pdfIn PDF document text
    • https://popetufuwude.weebly.com/uploads/1/3/1/4/131483025/0af8adf5141.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373509/normal_60152c191867b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503874/normal_6042d493247a0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490725/normal_601c8e57a2814.pdfIn PDF document text
    • https://pabifiliponisod.weebly.com/uploads/1/3/4/3/134367040/5a447c6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382638/normal_6015480f7693f.pdfIn PDF document text
    • http://stankoff.org/child_shirt_size_guidebb0mz.pdfIn PDF document text
    • https://vavixama.weebly.com/uploads/1/3/4/4/134471840/1932958.pdfIn PDF document text
    • https://korudodigujoko.weebly.com/uploads/1/3/0/7/130740169/kenutaj.pdfIn PDF document text
    • https://pemolopudamas.weebly.com/uploads/1/3/4/7/134753943/9e3d17932.pdfIn PDF document text
    • http://levantemosaic.com/lanokepigewunozofelorilubmykyl.pdfIn PDF document text
    • https://noresewikikizi.weebly.com/uploads/1/3/1/4/131453465/3298627.pdfIn PDF document text
    • https://bekitatabegoze.weebly.com/uploads/1/3/0/7/130775701/satokage-petopawage-tuxunav-fimejuxi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://1261df91-4e32-40b2-8b8a-4050d3c54cbb.filesusr.com/ugd/df69c1_2b724ab4aa8d46029b466f17a385ec1f.pdf?index=trueIn PDF document text
    • https://37e79482-e567-4eff-b449-6ea9b90d4679.filesusr.com/ugd/cff0cd_d4970f0579fa4123bf1c26c4e2b98cd9.pdf?index=trueIn PDF document text
    • https://6c036dbd-b327-4678-b778-de8a2ee7bb50.filesusr.com/ugd/ed64d2_7205756757ea40eca8c1b7beffdb5756.pdf?index=trueIn PDF document text
    • https://a9864912-ad24-422b-99f3-2d90f7703507.filesusr.com/ugd/d6af85_b0941ed52c104bd8a6abecbda709ead9.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f10d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF10D 5076 bytes
SHA-256: 4e9a3a3def67ed0737d275bfccd3c4b72c9330a1b8632e3a0b0caf6685008918
font_01_sfnt_off00010236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10236 10948 bytes
SHA-256: e75f1e8753a56dfe6e40eb37c963a202f9e0197251db9c65167b1ae72799944e
font_02_sfnt_off00012750.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12750 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333