Malicious PDF — malware analysis report

Static analysis result for SHA-256 843f37edcf27438f…

MALICIOUS

PDF

87.5 KB Created: 2021-08-02 22:23:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 21cd84d4974956e61e5a581dd99c37bd SHA-1: b9cec4bef5ab022412aa45ecc2bd1d5b2c4a5e27 SHA-256: 843f37edcf27438ff01ad24df914a236e1512856731cc2b454843e439d2451fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised CMS upload locations, indicating an attempt to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/160a4da361e707---vixijokofetazoguk.pdf In PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/b5n2k7va59108s0pi61lqnv2vn/kudamadegomisemorime.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/12485165.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607d633586fab---62738881680.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/47062357284.pdfIn PDF document text
    • https://habibitours.org/ckfinder/userfiles/files/nimavodujin.pdfIn PDF document text
    • http://hobbstownis100.com/clients/6/66/66141d04a4341350d76ae3a38785cb5a/File/kugofesizagiwobarixu.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/kanajebi.pdfIn PDF document text
    • https://northcoteplaza.com/userfiles/file/23582568464.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/92487168808.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1622850396.pdfIn PDF document text
    • http://velocimapper.com//webfiles/file/sopubibotulo.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/22629896826.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/vanidufuju.pdfIn PDF document text
    • http://internationalbeautypageants.com/clients/8/8c/8c0f0497d7166b07b5568c04be8084ca/File/16132916912.pdfIn PDF document text
    • https://dpengineers.info/admin/userfiles/file/semubogojurikopuravix.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074387d7541b---22225284220.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/68922539478.pdfIn PDF document text
    • https://yellowstonewildlife.com/98373988629.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4a7b8f742---58666702682.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/vukarekonivev.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/18310937718.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/fonavubojenol.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/toteletirekagusu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=oneplus+7+pro+official+android+10+updatePDF 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_off0000efdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDB 10964 bytes
SHA-256: 64ebf63cf7bd311f98a89d91b8373b64b46c145d6e1f1ed2eea0fb3550d79d0e
font_01_sfnt_off00010982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10982 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12194 17628 bytes
SHA-256: 7ae8c43ae49378cc62c85844c75e7700802b78d46720d990dec4eaa9ad1f9573