Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a6f33960e149227…

MALICIOUS

PDF

81.3 KB Created: 2021-10-07 12:12:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 6f0019ef323b179019f94c8811abf638 SHA-1: 1b39009e180a119d91cdd96e7f56ead432eaa3f5 SHA-256: 8a6f33960e1492271c6c0b4668ecad3893027555783e9fadb704916e3ba0d398
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly suggests malicious intent. While no scripts were explicitly extracted, the structure and URL patterns are consistent with a phishing or redirection campaign, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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://infrive.ru/uplcv?utm_term=how+to+add+prefix+in+excel+column PDF link annotation
    • http://alpha-cp.com/userfiles/file/31683209353.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/aa304d53a3a02fde97d712a034e465da/regidapixigarexulawajidi.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210909194717.pdfIn PDF document text
    • http://campfirewtx.org/userfiles/file/nedubirunorizotipadiva.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/deraza.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/67931476817.pdfIn PDF document text
    • https://gopherscopes.com/userfiles/file/29367174798.pdfIn PDF document text
    • http://stainless-faucet.com/uploads/htmlupload/files/81427416282.pdfIn PDF document text
    • http://unite-chem.cn/upload/files/pufezodino.pdfIn PDF document text
    • http://uat2.hkha.com.hk/ckfinder/userfiles/files/57463012340.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/50883735251.pdfIn PDF document text
    • http://nature-revive.org/files/file/rumajez.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614fd6e681ddf---ziketun.pdfIn PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/35247850405.pdfIn PDF document text
    • http://hwayoung.kr/upfile/files/16798289142.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/kexinu.pdfIn PDF document text
    • http://unstitchedfootwear.net/files/file/rekenufevume.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109122222456354.pdfIn PDF document text
    • http://romengo.com/ckfinder/userfiles/files/pozopit.pdfIn PDF document text
    • http://ternovykh.ru/content/file/71164200808.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c71e8bd3e9---rafamakoridakabevano.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/76161436097.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614eef357e2a6---81457095645.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/dikevexaligo.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_off0000d4ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4BA 19184 bytes
SHA-256: 66d49833054ab53c2aa3d228629fbf10246a65827012b4889831ce74597b6128
font_01_sfnt_off00010681.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10681 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E98 10892 bytes
SHA-256: 3ee54b8fa62c83e12fe2ffd726453ee9761594f1c71902fda0e24ff454ed35cb