Malicious PDF — malware analysis report

Static analysis result for SHA-256 90b4d0d8b71cab03…

MALICIOUS

PDF

83.2 KB Created: 2021-04-26 16:04:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 4183956d99bccdee81bcf357403564cd SHA-1: e49eea2649cf2466eb0d74e94a4ff24ca8249e26 SHA-256: 90b4d0d8b71cab032d32ce8693353eb8102a4d8a0429472cd93bdaa10e3513a0
244 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to disposable hosting, and one specifically to a redirector disguised as technical support interview questions. This indicates a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=ibm+technical+support+interview+questions+and+answers+pdf In PDF document text
    • https://cdn-cms.f-static.net/uploads/4375199/normal_6015fead5ecbf.pdfIn PDF document text
    • https://falababipudin.weebly.com/uploads/1/3/4/8/134847750/4690253.pdfIn PDF document text
    • http://cybety.xyz/benopoo84af.pdfIn PDF document text
    • http://amsidisi.xyz/sedegej1oam.pdfIn PDF document text
    • https://fakodide.weebly.com/uploads/1/3/0/8/130874451/550375eb53a5d.pdfIn PDF document text
    • https://zoladikadaxupaj.weebly.com/uploads/1/3/4/6/134635808/sopojokoso.pdfIn PDF document text
    • http://shoop-fe.ru/tmnt_2007_pc_game_setup_free_download9l343.pdfIn PDF document text
    • https://vowomupow.weebly.com/uploads/1/3/4/8/134846305/3dc57526a.pdfIn PDF document text
    • https://femevidawivuk.weebly.com/uploads/1/3/1/0/131071063/fozek.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450632/normal_5ff81500afba8.pdfIn PDF document text
    • https://metenesepagozo.weebly.com/uploads/1/3/4/7/134710396/goxitunubiwuwe.pdfIn PDF document text
    • http://potolkilife.ru/john_lewis_bed_sheets_kinglqy7g.pdfIn PDF document text
    • https://kokarino.weebly.com/uploads/1/3/5/2/135299240/2b6788526b.pdfIn PDF document text
    • https://ranemexamegen.weebly.com/uploads/1/3/4/4/134440137/2545038.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://9ebe8999-295a-4f11-87dc-c96f3e1b46ff.filesusr.com/ugd/8de238_27fe7bf8882a484885a86530e75ede50.pdf?index=trueIn PDF document text
    • https://6db1e9a2-4282-4636-8d41-de07325ad911.filesusr.com/ugd/d97b38_fb5c3a5253374f1d8963a99320eada5d.pdf?index=trueIn PDF document text
    • https://eaae50f7-3b1c-4f1b-9b3c-e2a48377569d.filesusr.com/ugd/b96e41_160e807581474e8993ea917e49471cb1.pdf?index=trueIn PDF document text
    • https://cd8fad78-6a19-43c6-878c-830d169ee42d.filesusr.com/ugd/ff0d91_62b877bc11544c27947a5d510261db75.pdf?index=trueIn PDF document text
    • https://d3df31c7-72fe-42b1-a92e-0723e8ed7a16.filesusr.com/ugd/5bf82b_5150c26af36b424c90dffe9fb1d832dc.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_off0000f8d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D5 5632 bytes
SHA-256: 97fe349762af5c1c5a66e9eca0217f1ecf1bb2501c7bd5a930277604d17d7b57
font_01_sfnt_off00010bd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BD5 10832 bytes
SHA-256: 6f0e5e3787d2016b6b63e87af817d22b40b40088263213ec3e9c7c165be49d3b
font_02_sfnt_off000130bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130BD 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34