Malicious PDF — malware analysis report

Static analysis result for SHA-256 998da14b6938cd7d…

MALICIOUS

PDF

78.7 KB Created: 2021-09-21 08:41:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 035437d99a63433904539dc665473cd2 SHA-1: cd302ea0b97363215980fe4ad3d3ff33ff30e775 SHA-256: 998da14b6938cd7d433f26e53e5fd5a02179ca19fedbf6966b824e075d405a8c
136 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on multiple compromised websites, a common tactic for distributing malicious payloads. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' indicates the document likely instructs the user to open a password-protected archive, a method to bypass initial security scans. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://congtrinhnhaviet.vn/upload/files/63380920663.pdf
    • https://novamakine.com/upload/ckfinder/files/13502405357.pdf
    • http://ritadas.in/userfiles/file/35584107917.pdf
    • http://globalsublimation.net/uploadfile/files/30101373868.pdf
    • http://fixafilm.se/userfiles/file/42578818462.pdf
    • http://www.farmaciabergua.com/userfiles/files/29174578192.pdf
    • https://h1t-url12shio-turbo.com/contents/files/44372987094.pdf
    • https://o-dance.com/upload/files/wetivagavuwegulemoferoti.pdf
    • http://synphabase.ch/upload/file/pokusepujubulixisivetun.pdf
    • http://fishtech.org/uploads/userfiles/file/file/96167852153.pdf
    • http://sspvjd.com/FileData/ckfinder/files/20210903_80F8770D29D06ACC.pdf
    • http://mn-print.ru/ckfinder/userfiles/files/18719485899.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/16148157c503f9---wumaritu.pdf
    • http://papaicountrylodge-longstay.com/user_img/files/4440242488.pdf
    • http://tabletopad.com/images/file/32499108617.pdf
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/57546003428.pdf
    • http://www.pes.edu.mn/ckfinder/userfiles/files/xazuwexukimawa.pdf
    • http://unseretochter.ch/images/file/61424975343.pdf
    • https://spacio.hk/attachment/file/nigoxokexoxosunupesapuji.pdf
    • https://rusepress.com/uploads/wysiwyg/files/55963284207.pdf
    • https://libyamonitor.com/sites/all/libraries/ckfinder/userfiles/files/penexagolirijetabuli.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143afccc25cf---dasanoxap.pdf
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614256efb2276---kevivugiviguboberateka.pdf
    • http://life-worldwide.org/assets/uploads/files/37934198517.pdf
    • https://angkalaris.com/contents/files/89032905505.pdf
    • http://patp1ryb.ru/media/file/36363890946.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=coordinate+pictures+worksheets
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cfe1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFE1 16792 bytes
font_01_sfnt_off0000e7f3.bin
2b8042e3754b1f84d99bcd5cad9568c0e9df455ce47b9c4f0cdfa8d92018a3e0
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F3 16956 bytes
font_02_sfnt_off00011398.bin
a261e39ef9428d7ede068c1fd0c1888034bae6aa8fec22e790bae288491e78c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11398 10876 bytes