Malicious PDF — malware analysis report

Static analysis result for SHA-256 885f66b261b42d32…

MALICIOUS

PDF

101.3 KB Created: 2021-03-10 16:43:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 3a27b8aa310fab2688b5ad27fbc65582 SHA-1: 2a0f303917bfed61b05c9b6753c8d845a4a7a760 SHA-256: 885f66b261b42d327249b57221b61a9970ca1e599e24ea76b8669dd2553dee85
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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://mezovuduw.ru/strik?utm_term=staff+nurse+entrance+exam+questions+answers+pdf PDF link annotation
    • http://dizititakozazi.mywebcommunity.org/89852102284.pdfIn PDF document text
    • http://vaxenovutejuzid.sportsontheweb.net/what_does_error_code_ae_mean_lg_dishwasher.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/lonozote/43728963396.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8845ea39-1a47-4dac-97e4-800c49a8438c/janesozefulaninurimes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3c222e9-09fd-4177-b31b-dd15b113972d/96994260733.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/165007cf-7175-43c3-8296-518a9255a881/chetan_bhagat_one_night_at_call_center_free_download.pdfIn PDF document text
    • http://zerowegujij.onlinewebshop.net/subordinating_conjunctions_song_itsy_bitsy_spider.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3612eab9-fbcc-43e2-b8b9-4e0ad24ee84f/fuwekibefu.pdfIn PDF document text
    • https://s3.amazonaws.com/jolituzoji/81319030103.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/320d952b-ae58-4603-9f79-995d44299c52/bumojejonikutera.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f13e2f77-2178-478d-9fae-90ac813cbe24/traits_of_good_academic_writing.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f1e1eda-de28-446b-88f6-8c78524797d0/why_does_my_panasonic_remote_control_not_work.pdfIn PDF document text
    • https://6f8cb219-4830-455d-9ced-b55e65700e85.filesusr.com/ugd/fd30ac_cf6e32ea76fd482c8c7af881a7fa1843.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vebisop/gekasolefedajuzobu.pdfIn PDF document text
    • https://61df3396-90b5-4b69-a3ae-475c9da6ebc5.filesusr.com/ugd/516574_aa54ba40682f47f2b2b0bc78bcef9c6b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb714512-18c7-4a86-85b3-966b008e4ffe/bosch_silence_plus_44_dba_mounting_brackets.pdfIn PDF document text
    • https://s3.amazonaws.com/xufaxoferugod/25405008092.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/904e64b2-efcc-4cf2-9c04-8d6f67b15a62/84308170040.pdfIn PDF document text
    • https://s3.amazonaws.com/vibuvomomuv/game_brother_in_arms_apk_obb.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/22aaa831-e7a7-474b-b74f-679d84fd1ba0/nefazevuxakosafuzi.pdfIn PDF document text
    • https://1b2c4efd-c8eb-4b04-b26f-b9154d704720.filesusr.com/ugd/d3758e_9a279d51f99c43478bee9967ac541cc7.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00014cd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CD9 5656 bytes
SHA-256: eaa83a2b791b0a171b0b55353e55442feeefe448cdd368231321856d39c243d5
font_01_sfnt_off00016023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16023 11484 bytes
SHA-256: 974f3a591e0d9360de5ad23d1c9b8b52fe0fdab5b709811695df8abd3a4916fc