Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc42bf3d1d28b6c7…

MALICIOUS

PDF

78.6 KB Created: 2021-06-11 07:36:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: a78779b67a8a064c427cbc1a7ead5ad7 SHA-1: 14b696e1e42f4d1286425aefded057dcef8bda28 SHA-256: fc42bf3d1d28b6c7032323cbf95211828b48611eeec676c1177bf126a3342af7
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It contains a significant number of external links, many pointing to disposable hosting, suggesting a link farm designed to lure users to malicious sites. The document body, though heavily obfuscated, appears to be related to an 'answer key', a common lure for phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://synerhu.ru/pbw?utm_term=gina+wilson+all+things+algebra+llc+2014+2017+answer+key PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4408195/normal_5febf2fe98337.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378606/normal_60112e8ae1f55.pdfIn PDF document text
    • https://simokodopegaliw.weebly.com/uploads/1/3/0/7/130776428/5398856.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367648/normal_606802edc5893.pdfIn PDF document text
    • https://lukawonudos.weebly.com/uploads/1/3/5/3/135320707/e6545c195d4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484605/normal_5ffacd8e613d1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418970/normal_6051379c7d23d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445888/normal_60c22d2356334.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420260/normal_5fe518a024e7a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465565/normal_60350c77f0b60.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486971/normal_60348f4e5cbb4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446643/normal_601db39b65e67.pdfIn PDF document text
    • https://selikiwomutarew.weebly.com/uploads/1/3/5/3/135329437/newijanitep-xagav-porapa-piwuz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://ruwomodanom.pbworks.com/f/botokalokodozerefelaze.pdfIn PDF document text
    • http://jetubabup.pbworks.com/f/70420383344.pdfIn PDF document text
    • http://nimogomaw.pbworks.com/w/file/fetch/144716592/what_are_some_good_rules_for_a_discord_server.pdfIn PDF document text
    • http://xozojonurom.pbworks.com/w/file/fetch/144947541/50212950580.pdfIn PDF document text
    • http://nadupodifado.pbworks.com/f/11678548454.pdfIn PDF document text
    • http://gokewisu.pbworks.com/w/file/fetch/144737025/bemap.pdfIn PDF document text
    • http://bazibenis.pbworks.com/f/spanish_prepositions_practice.pdfIn PDF document text
    • http://momukaduwe.pbworks.com/w/file/fetch/144886134/fill_form_10c_online.pdfIn PDF document text
    • http://zuwofig.pbworks.com/f/drivers_license_template_psd_free_download.pdfIn PDF document text
    • http://fijinatuzut.pbworks.com/w/file/fetch/144605355/kymco_agility_200i_review.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_off0000f03c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF03C 5984 bytes
SHA-256: f01a094cb7e9d0cabf4f911073b05bbf8349be76946d34dcbb9493e8a08980a5
font_01_sfnt_off000104c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C6 11108 bytes
SHA-256: 724e018eaf72c5d00e470cfde4e5b35baa896474b413dc4185cc96a862e9fa43