Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad902a76ac929882…

MALICIOUS

PDF

69.7 KB Created: 2021-09-25 02:05:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 91c76caf02192cba94ff89decec0bee1 SHA-1: 98f3d768bc1572c02dae75deedb9cc8273516363 SHA-256: ad902a76ac929882c233c2b6fae46e4fe302dbd4575ee002ce24abf8f1df5a64
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. It contains a large number of external URLs, many pointing to potentially compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads or phish for credentials.

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
  • 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://laborke.ru/uplcv?utm_term=nexus+5x+android+9 PDF link annotation
    • http://first-group.kr/ckupload/files/siwakodulotewozaze.pdfIn PDF document text
    • http://internet-trade.eu/UserFiles/file/40289138730.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/32864850875.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/33894903928.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/kumijagirebovedifop.pdfIn PDF document text
    • https://ku4ysk-9lgp4y.com/contents/files/wugabusirexikozenazuzuja.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/17777254482.pdfIn PDF document text
    • http://sanruou.com/app/webroot/uploads/files/70374854290.pdfIn PDF document text
    • http://kcwoman.medsoft.kr/pds/userfiles/files/56921266586.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/12861102078.pdfIn PDF document text
    • https://qfuse.it/images/uploaded_files/ckfinder/files/1630685602_9014a1ca35.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/tapoxe.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e4b6a1b405---gunajupebesatasul.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed33d1fe5a---36415126585.pdfIn PDF document text
    • http://liubeauty.com/luutru/files/manobemegimuwetilavigoz.pdfIn PDF document text
    • https://mb-classic-service.de/userfiles/file/83366715267.pdfIn PDF document text
    • http://apvn.info/userfiles/file/70447672490.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/tejemafonuwupofefedaz.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16135e480c1577---zurutobuvikupojugibo.pdfIn PDF document text
    • http://blueview.nl/app/webroot/files/userfiles/files/goxopeju.pdfIn PDF document text
    • http://rrbrentacars.com/files/others/17467263015.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/viloxifikag.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_off0000aead.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEAD 16976 bytes
SHA-256: abfe0fe7bb6031572571b9b086abc7607e13327be2a8e59e7bda187c073187c1
font_01_sfnt_off0000d99b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99B 10576 bytes
SHA-256: 98d35a3a21d789eb9066b6aceb983f5587d2075bc256f7507aa9e929a5a9010e
font_02_sfnt_off0000f1ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1