Malicious PDF — malware analysis report

Static analysis result for SHA-256 b43475c5b9fce444…

MALICIOUS

PDF

74.2 KB Created: 2021-02-23 09:33:05 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7d65e6dfa068ac58aadb342f369cd1fe SHA-1: 723d6a963f58ae6dcf9388bb2f17087440556b09 SHA-256: b43475c5b9fce444e15e6c0eb2dc19d7ddbd85c40ee03c9bd140a77a9befbada
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which are part of a link farm designed to direct users to potentially malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and extensive external linking suggest an attempt to exploit users by directing them to compromised or malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jacksth.ru/strik?utm_term=how+to+forward+calls+on+toshiba+phone
    • https://cdn.sqhk.co/kumipexa/e5Cjcgc/orbia_tap_and_relax_apk.pdf
    • https://cdn-cms.f-static.net/uploads/4402712/normal_6023de08ef622.pdf
    • https://cdn.sqhk.co/razanifuwuz/d1iiibb/candy_crush_saga_level_6013.pdf
    • https://cdn.sqhk.co/ganuniwiku/e23jggf/outdoor_survival_skills.pdf
    • http://jopalebifu.iblogger.org/zenedujiwub.pdf
    • https://cdn.sqhk.co/fepefudasor/hgichai/bbc_dinosaur_world_game_free_download.pdf
    • https://ginekimef.weebly.com/uploads/1/3/0/7/130738874/matebedusix-pegodaratuxudo-ziguxus-lejufavex.pdf
    • https://cdn.sqhk.co/gojelonub/qjggdjc/mesat.pdf
    • https://static.s123-cdn-static.com/uploads/4391634/normal_5fdf3d1d0e93e.pdf
    • https://cdn-cms.f-static.net/uploads/4413231/normal_600be51e4d474.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://lokimutopilar.epizy.com/65464205870.pdf
    • http://vitafunajubala.rf.gd/heart_failure_management_guidelines.pdf
    • http://koxowasone.epizy.com/android_google_drive_backup_photos.pdf
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e433.bin
a88c68c9ecb609e11cb9b206b2fc12671b10854bf958a06af61625592c5dba03
pdf-font-stream PDF embedded font (sfnt) at offset 0xE433 5436 bytes
font_01_sfnt_off0000f6b7.bin
2f5da4c98a23847fc22fbaa07f6ee8fc7c298b8165968a25eba5d267d6ec669b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B7 11080 bytes