Malicious PDF — malware analysis report

Static analysis result for SHA-256 b385eecdf4987c7b…

MALICIOUS

PDF

76.8 KB Created: 2021-09-09 20:20:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f8988ac6e124df8458edbbcad033e306 SHA-1: 7edfb91a87302f72965c6383672ab212a6b90ec0 SHA-256: b385eecdf4987c7be258e98ab662860d175e283956fc9c0b9a7cb7df433ef740
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple links to external PDFs hosted on disposable domains, indicating a phishing or malware distribution attempt. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest this is a lure to download further malicious content. The ML classifier and ClamAV detection further support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://about-dogs.ru/upload/file/kafekomutabupadovu.pdf In PDF document text
    • http://fitviewer.com/files/file/98545074723.pdfIn PDF document text
    • http://xmzhj.com/UserFiles/file/budamuj.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/ditotulofiresojedavi.pdfIn PDF document text
    • https://innovativallatgyogyszer.hu/fileok/file/31155590152.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/fazajojewuk.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/37241817564.pdfIn PDF document text
    • https://digireg.lu/upload/buganegisi.pdfIn PDF document text
    • http://jlm-kg.com/uploads/file/pinenipidananotu.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/nexuzerevojafalerutugop.pdfIn PDF document text
    • http://swiss-ex.com/images/blog/file/tapedigatefi.pdfIn PDF document text
    • http://pitin-akutsu.com/js/upload/files/rilorederinokosapofowiz.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/64005485553.pdfIn PDF document text
    • http://c2r.su/uploadfiles/file/2021090314570773499.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/xizegubojo.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/tobagakodipivepunikegubar.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138b07f2846c---joxojesurupukupifox.pdfIn PDF document text
    • http://ipsaix.com/ckeditor/ckfinder/userfiles/files/20404637540.pdfIn PDF document text
    • http://stopguepes72.fr/userfiles/file/pakedonajenigozi.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210901085211.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/66168717282.pdfIn PDF document text
    • https://ceylanotel.com/firma/files/dusadogemofi.pdfIn PDF document text
    • http://dycelife.com/userfiles/file/48864993640.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=putlocker+friday+night+lightsPDF 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_off0000c878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC878 16812 bytes
SHA-256: f5b9f7695bd5dea68cdf9a192d6444302b99d21ba79bfddfba2cb7190ff163a6
font_01_sfnt_off0000f415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF415 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C2C 11064 bytes
SHA-256: 5a294020a3ddceebdab3a1a08ae623f553adb3054a7ec8bb64b7d30ea6b7b6db