Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3c916394addde6e…

MALICIOUS

PDF

67.0 KB Created: 2021-06-06 05:09:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 1af0e87890d9989df3b01408b5b750d3 SHA-1: e923b1fd6123a4b0a967a503a8662f49576fd20e SHA-256: d3c916394addde6e11bc09c4c21ac62239f48f4d5d1a7de5a15a47c93e1bf2fe
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The primary malicious URL identified is 'https://inwebjor.ru/pbw?utm_term=bunnicula+book+pdf', which is likely used for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://inwebjor.ru/pbw?utm_term=bunnicula+book+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4460950/normal_606bf193a05f5.pdfIn PDF document text
    • https://kufazijofiw.weebly.com/uploads/1/3/0/7/130776126/defesanumigid-zotesejenad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450734/normal_60161ce1c6e0f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417308/normal_601bb70b4656f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409797/normal_60108e2d4841d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410214/normal_602c33742df02.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4482012/normal_60b359a5baeb6.pdfIn PDF document text
    • https://sajefabavasa.weebly.com/uploads/1/3/2/7/132710755/xixoxutuwibubozemo.pdfIn PDF document text
    • https://kidupexedu.weebly.com/uploads/1/3/4/6/134683121/5035072.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403561/normal_600a6155308bd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/e7e8805a-260f-4dce-8a45-40f99c87a58f/hp_elitebook_8540w_drivers_windows_10_64_bit.pdfIn PDF document text
    • http://joxupakager.pbworks.com/w/file/fetch/144668688/seagull_assistant_apk_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d9d42691-8485-452b-9a45-e0a3b52fd9a2/captain_underpants_movie_2021.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f0537a1-d51c-4e6d-9ca8-f545017b2ad0/hey_little_ant.pdfIn PDF document text
    • http://fadoposapat.pbworks.com/f/rasisizotolevonom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7ad76c02-42ea-4368-ad5c-519c1500ff5a/920xt_user_manual.pdfIn PDF document text
    • http://wisarazed.pbworks.com/f/how_do_you_calculate_the_weight_of_corrugated_sheets.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b1deb03f-e9dd-47aa-907f-001bad5d93c4/vozumidirasamep.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4202e479-4fec-4ce4-851c-b25bf33873a7/why_has_my_sky_remote_volume_stopped_working.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ed95477-4f64-4d63-b64b-77d2a9b56d37/61769426761.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b37dcc66-d8a7-4afe-8df6-2b2cda18797a/auto_mechanics_fundamentals_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57c79d3f-8ceb-4aaa-a201-c14016a1f1ac/zugoxisivamesutisizos.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_off0000caaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAAF 5128 bytes
SHA-256: d82799af36d343eb8dde19c13876d46b0c720dfa758a5b18283becde9aa284e6
font_01_sfnt_off0000dc39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC39 10232 bytes
SHA-256: 37e3270f356492f0d5a0de69f0db7cfb13476a55d2b43a1697a20f4122016921