Malicious PDF — malware analysis report

Static analysis result for SHA-256 49aa3e534e990639…

MALICIOUS

PDF

85.0 KB Created: 2021-06-22 23:28:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 20d805458f14642ecca185057d3b7da0 SHA-1: d214f6f2798d46a6ea8b92631b0fa2017b090029 SHA-256: 49aa3e534e990639ff5c7c5ea661498e32d524ba9fff904dbcb4afde1cdc2898
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the document is a link farm, with many URLs pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to distribute further malicious content or phish users. The document body, though heavily obfuscated, contains references to 'Class 10 telugu textbook', likely a lure to entice users to open the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://barudan.hk/UploadFile/file/20210610224909343.pdf In PDF document text
    • http://payassistinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074720f147a3---zexikonefixoju.pdfIn PDF document text
    • http://archerelectricsupply.com/userfiles/file/zojukuturobinavuzajazu.pdfIn PDF document text
    • http://interiorconsignments.com/media/file/30785863734.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/12307389508.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3ccb9c9d2---64197506378.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/idfqjf5ih7a0jfsbecglt3k36g/52327576696.pdfIn PDF document text
    • http://profesniprukaz.cz/ckfinder/userfiles/files/11891937385.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609b50f974e38---karepopanat.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c67ecc8494f---xipoz.pdfIn PDF document text
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f250191420---rafabifamidoneleda.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb8f092a600---medewexepafizelurazo.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075c2d19fda4---27274365564.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/ob0hqe2ji8tn6ese8i8u0gj6k0/39563888823.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=class+10+telugu+textbookPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7C5 5128 bytes
SHA-256: eed088529ac2332c7f3daa68fc544c73eda03bfaebd046fc527841cb46819c00
font_01_sfnt_off00010950.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10950 2664 bytes
SHA-256: 0b47d1b51a613d5ef1d219ab01f1758b78951940138d90d1f49828faaea457db
font_02_sfnt_off000114c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114C1 11040 bytes
SHA-256: cf60486671925ef1297b69958ec4ce69339ed9e33acc57039cb95cc03785dcda
font_03_sfnt_off00013a86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A86 2936 bytes
SHA-256: 9b580332265e7ad350f5d239d4b235741a14708ce91604cce89b795304fbbece