Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b2f8bcfc6d91bc8…

MALICIOUS

PDF

83.1 KB Created: 2021-09-04 20:57:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0eee3f58bc5bf96bcb9d428129f7473c SHA-1: f3951d7dfe9f932bed79de3e9dd9f358ccc4cd0e SHA-256: 5b2f8bcfc6d91bc89994f9b8a6c2ef0b2faccdd3fdb35a32d705b3fdb12a5faf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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=normalization+in+sql+server+pdf PDF link annotation
    • https://kimcert.org/E/file/29257033679.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/14605932270.pdfIn PDF document text
    • http://marty-triple-m.ch/inhalt/files/79123451269.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/16332072710.pdfIn PDF document text
    • https://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/so8oejm8q4vgi43igmr194dhhc/1906770154.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/16cce02d97f723e5cf0a1d98f3a49ff3/18867635931.pdfIn PDF document text
    • http://fkm-lux.by/var/upload/file/96378858981.pdfIn PDF document text
    • https://atraba-holding.com/userfiles/file/13266992728.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/ruroxegupubapigigivuru.pdfIn PDF document text
    • http://turnyras.lt/Files/file/71761519250.pdfIn PDF document text
    • http://ceomit.com/fckupload/file/warutidagugevesolux.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/9d01c3447eb714beb4b1b336a78005f2/81856146996.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16079f7c0abd2a---bubakogapoxak.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/vexeretevilaleriz.pdfIn PDF document text
    • http://pc580.cn/upload_fck/file/2021-8-20/20210820074733542241.pdfIn PDF document text
    • http://logopeda-empatia.pl/content/file/jisotokiwunog.pdfIn PDF document text
    • http://jinwoosmc.com/userfiles/file/72577287724.pdfIn PDF document text
    • https://dintek.eu/uploads/file/kowokimoxeriverunekunuku.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b52446689---bafofafogogitawulaluva.pdfIn PDF document text
    • https://kclandscapes.com/ckfinder/triplebuserfiles/file/67016975082.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/f6uctut4g3a6b40258282v8vi0/49143147629.pdfIn PDF document text
    • http://sobsai.com/ckfinder/userfiles/files/9206755262.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_off0000e103.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE103 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f91a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF91A 10908 bytes
SHA-256: f6d37e4c4da0e476bfeab23e59dc6363ccfd01675925c4c94e609d6bb40ddf2c
font_02_sfnt_off0001122b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1122B 17108 bytes
SHA-256: b9adf5829c16b483d8e3cce16355e8d1f42892381120acdbfa93b96c70274ed8