Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b2221f46f18841…

MALICIOUS

PDF

74.6 KB Created: 2021-02-24 05:05:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: d2e2b0d46221741904e728963dd5beb0 SHA-1: c9b8f01122899e7b37ef7f5bd24b6f780587d1bc SHA-256: 71b2221f46f188416a7f72b5ba9e110578bc5a94d18fac526f8ea233eaf68a07
184 Risk Score

Malware Insights

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

The PDF contains multiple embedded URLs, with a critical heuristic firing indicating it links to known malicious redirector infrastructure. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains text related to 'Aa step 8 and 9 worksheet', likely a lure to entice users to click the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 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://yafferge.ru/strik?utm_term=aa+step+8+and+9+worksheet In PDF document text
    • https://cdn-cms.f-static.net/uploads/4375503/normal_602ab4baf3928.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402949/normal_5fda11a11ccd2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379387/normal_5ff77f89e6ad1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450038/normal_5fe11261aa22b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415292/normal_5fd3b555509d8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4478655/normal_5fdec3fd51c6d.pdfIn PDF document text
    • http://greyfruit.space/tor_browser_for_pc2tvij.pdfIn PDF document text
    • http://niwuzukemidepiw.iblogger.org/8096389678.pdfIn PDF document text
    • http://kelirajisob.66ghz.com/99562988856.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374535/normal_600e0e023f6d1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380384/normal_602eb48b9f5e0.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bokatamekal.rf.gd/literary_elements_list.pdfIn PDF document text
    • https://s3.amazonaws.com/lixuzo/beam_bending_moment_diagram.pdfIn PDF document text
    • http://sopigovo.rf.gd/42049770558.pdfIn PDF document text
    • http://betiravel.epizy.com/digolatifereb.pdfIn PDF document text
    • https://s3.amazonaws.com/jedadokuti/questing_guide_classic_wow_alliance.pdfIn 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_off0000e4f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F0 5512 bytes
SHA-256: 76496895ecd8c6b20a478e3fd867bfd9244fc310c4dbfde745e76bdc9394d892
font_01_sfnt_off0000f7b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B9 11668 bytes
SHA-256: 4a40001ab416ba3ae66c5939f2ce43e9a07e9e77eec55c414936f01e1a38d045

Open this report in the interactive analyzer, or submit your own file for analysis.