Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c21561b46529f40…

MALICIOUS

PDF

81.2 KB Created: 2021-09-06 12:53:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 72678e5fceec9feebdd59a7713b53d0c SHA-1: c097ca4f5a6092967842213490b18c16d52026ea SHA-256: 3c21561b46529f4086c2a5812175a9657d1aa05e488a78f3ee7591971091014d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on compromised CMS uploads or disposable domains, suggesting a link farm designed to redirect users to malicious content. The PDF structure and embedded URLs point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://smidgel.ru/uplcv?utm_term=informatica+mdm+interview+questions+pdf PDF link annotation
    • https://airbays.com/userfiles/file/baliwilebelugeniliravo.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160872584a16de---27295857505.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160800567c6145---57429039645.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/9511675104.pdfIn PDF document text
    • https://embassyinvietnam.com/webroot/img/files/solexiworap.pdfIn PDF document text
    • https://nadrozmerne-sklo.cz/uploads/golimujogesutiriwepo.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/2ae6a99a24243f393ae238391a2a185d/58945697814.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/0146aad9cee8496edb4efddaf1c80ed5/32254951071.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/rakokizelekipefofuwatip.pdfIn PDF document text
    • http://saokienviet.com/uploads/image/files/78073293971.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609fcd4c7403e---kowowevuwivinovem.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/4ced3f2b98072abd91e430f8d4840870/36366307722.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/lejubudegisurinejumuw.pdfIn PDF document text
    • http://fosterfreezesantarosa.com/uploads/files/53980625476.pdfIn PDF document text
    • https://patoman.ro/ckfinder/userfiles/files/potomazadomikowuf.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160850af19de23---xozumifotidiseduw.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1629780968.pdfIn PDF document text
    • http://tlproduct.com/userfiles/file/bofebasedi.pdfIn PDF document text
    • http://madinagirls.com/easydo%20v2.00/files/uploads/38120162887.pdfIn PDF document text
    • https://noddy.nu/images/file/1348155764.pdfIn PDF document text
    • https://gites-les-bardots.com/userfiles/file/lexafugigogozefisefago.pdfIn PDF document text
    • http://onestudent.dk/userfiles/file/83736273248.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/lanudupogevur.pdfIn PDF document text
    • http://phuongdonggolf.vn/app/webroot/uploads/files/figonulusesawodid.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_off0000d7b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B7 17592 bytes
SHA-256: 8b2975e26525f94028c41db7c4cc06401ec762a2ac9fd3300da5d0335c8f4c47
font_01_sfnt_off00010554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10554 11084 bytes
SHA-256: 5c0b9d9b240930868bae30dd5b4a3f5bebdde0e2f3092c217dd8d3c45d3e4ecb
font_02_sfnt_off00011f09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1