Malicious PDF — malware analysis report

Static analysis result for SHA-256 3611c5692351f8e1…

MALICIOUS

PDF

77.0 KB Created: 2021-09-17 17:06:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 13786a57f52f40ed8d63aa6c34874407 SHA-1: 4201234c789a8585895380a33f226a3c05531d7a SHA-256: 3611c5692351f8e14c091d705baadb31f305942084453f18c3e9167aff60e307
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised CMS uploads, suggesting it's designed to redirect users to potentially harmful websites. The PDF structure and embedded links point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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
  • 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 https://synerhu.ru/uplcv?utm_term=the+willpower+instinct+pdf PDF link annotation
    • http://turagent007.ru/userfiles/file/84823538459.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/96745675988.pdfIn PDF document text
    • http://julianina.de/upload/file/34694686217.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/63qphpr50h1urs7lheavpnsqgu/58498116116.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/wanoled.pdfIn PDF document text
    • http://idealhca.com/admin/images/file/18609925134.pdfIn PDF document text
    • http://luxlustry.ru/img/upload/13080615923.pdfIn PDF document text
    • http://cesnek-vysocina.cz/UserFiles/File/53914618336.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/fosufifug.pdfIn PDF document text
    • http://artdealer.vn/upload/fckimagesfile/bd15cd6a12afd51f59fd8fd83579704b.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/vuripufufidajuzusisesi.pdfIn PDF document text
    • http://imapbook.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/genavaxitafaga.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/73161287747.pdfIn PDF document text
    • https://nguyenhungstone.com/uploads/image/files/51770613765.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411a9ca1bbd---17513463339.pdfIn PDF document text
    • http://lecostationery.com/files/file/66224988003.pdfIn PDF document text
    • https://kimansion.com/uploads/file/kivivipefaditabix.pdfIn PDF document text
    • http://talesma.com/E/file/50921827060.pdfIn PDF document text
    • http://travelshops.pl/userfiles/file/74349418939.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/mivediduwajoselinapotax.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/161449951098d3---pefagomajujugozup.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/zuzisejizixekizulomit.pdfIn PDF document text
    • http://kezheng.net/Upload/file/jexevosubapulewebotojod.pdfIn PDF document text
    • https://sitarasign.ir/data/file/91263741184.pdfIn PDF document text
    • http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/64733610323.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/fijutofibaludawaz.pdfIn 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://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_off0000c7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7F3 17796 bytes
SHA-256: 8bac2be2a79988b95f375ecab1c441420571357489ff43c5484e37fb3784b975
font_01_sfnt_off0000f653.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF653 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E6A 10604 bytes
SHA-256: fd5377acb09aeb605bbf9b5cc9865f7c71744feaf0499693099574b02cfc6e87