Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4eb9f83571db85b…

MALICIOUS

PDF

93.6 KB Created: 2021-09-08 20:50:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5eca71fb7652ccb75544c7853aa606ed SHA-1: 778377715e1f38229dd137dd8a352244c2d4542a SHA-256: a4eb9f83571db85bd931f7cd111963d21b2ada63691d81de7b6b0f7844ae7876
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier with high confidence. It contains numerous external URIs, many of which are hosted on domains that appear to be link farms or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of 'cmd.com' in the document text, along with multiple PDF_URI heuristics, indicates an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://hongdacable.com/d/files/dodalejuriko.pdf In PDF document text
    • https://cfacgroup.com/uploads/FCK_files/file/58620906100.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/34041841503.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/xaxikoxefi.pdfIn PDF document text
    • https://warsztatgdynia.pl/app/webroot/media/files/51493460335.pdfIn PDF document text
    • http://arenabilardo.com/data/_files/49888270120.pdfIn PDF document text
    • https://cmfnepal.org/userfiles/files/57323752343.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/ginosivapi.pdfIn PDF document text
    • http://qdcmd.com/data/files/74163383940.pdfIn PDF document text
    • https://nayyaralidada.net/alpha/ckfinder/userfiles/files/dokupizasuxegibakefasufim.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/koxunilafa.pdfIn macro / runtime command snippet
    • https://apotekatia.ba/fajlovi/66095390969.pdfIn macro / runtime command snippet
    • http://china-miyaco.com/img/file/202195144641.pdfIn PDF document text
    • http://fsgzb.com/upfolder/e/files/20210906203013.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/kelubat.pdfIn PDF document text
    • https://alpinebadmintonacademy.com/ckfinder/userfiles/files/61194744778.pdfIn PDF document text
    • http://bocghebinhduong.com/media/ftp/file/6014169552.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/94375425522.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/jujagokokovafoloruposasa.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/nisuxifil.pdfIn PDF document text
    • https://people11people.com/uploads/File/sodirik.pdfIn PDF document text
    • http://bkht.vn/userfiles/file/37713512640.pdfIn PDF document text
    • https://wecareu.net/ckfinder/userfiles/files/90272588990.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/51667070014.pdfIn PDF document text
    • https://nayyaralidada.netIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=fifty+years+with+the+golden+rule+pdf+freePDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB60 11056 bytes
SHA-256: f9f3a7f68cb4210deb422b8c000f1c33bb8b54b8bbec7ef85c692bf7c584cf90
font_01_sfnt_off000114e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114E9 22720 bytes
SHA-256: 588f5a3edc54c376680b150c89c081960207517f120f55982fd4b482927d73aa
font_02_sfnt_off0001502d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1502D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1