Malicious PDF — malware analysis report

Static analysis result for SHA-256 36ba72079ff4d613…

MALICIOUS

PDF

82.7 KB Created: 2021-09-16 15:25:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 321ecdf5046df31449f5deaa4e820000 SHA-1: 8d67937c44b14251677056c2477aa595ff61eb69 SHA-256: 36ba72079ff4d613fc225c431f305b6babbf317f29a7381a64c31d6e94fc3011
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are identified as link farms on disposable or potentially compromised hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or SEO spam. No scripts were extracted, and the document body was unreadable binary data, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://ketchas.ru/uplcv?utm_term=how+to+take+sms+backup+from+android+phone PDF link annotation
    • http://teresachild.com/upload/files/digajusul.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/biwojevuwotiwudesofaremo.pdfIn PDF document text
    • https://macintosh-szerviz-javitas.nuttydog.hu/ckfinder/userfiles/files/jofumakisiwafejikaje.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/bixokadudotaniwabarux.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/kusovebobogovokuzoteguzex.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/tiwuxulipo.pdfIn PDF document text
    • https://butzbacher.turnpoint.jo/app/webroot/upload/files/zodot.pdfIn PDF document text
    • https://blugarden.eu/file/63662431014.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614139fc1e2c3---mizuwunixepexibetivawuxub.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/batenewuwunevixopoboxu.pdfIn PDF document text
    • http://synfarm.com/upload/files/28903606239.pdfIn PDF document text
    • http://swiftnb.com/ckfinder/userfiles/files/10155518462.pdfIn PDF document text
    • http://gibisch.biz/files/files/80417512897.pdfIn PDF document text
    • http://costanzolegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/65609542063.pdfIn PDF document text
    • http://bycongroup.com/UserFiles/file/jisuxoworiwanadip.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/97843368136.pdfIn PDF document text
    • http://khlongtoei-nfe.com/library/userfiles/file/6274240025.pdfIn PDF document text
    • http://55pluscommunityspecialist.com/userfiles/files/8681418508.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140201ca8ecc---gemura.pdfIn PDF document text
    • http://immobilieninvestors.net/userfiles/file/vediwekonuruzefumokeseli.pdfIn PDF document text
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/98632214963.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613732e61f06b---1182934465.pdfIn PDF document text
    • https://oxfordjsr.com/userfiles/file/zubuteziz.pdfIn PDF document text
    • https://ferropula.hr/files/digijaxoxokarevasi.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_off0000dc81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f498.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF498 11248 bytes
SHA-256: 4d86fc8b41d038b629e0d2e86f332532b1365fa9e1713441644c966c1a15770d
font_02_sfnt_off00010e8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E8F 17996 bytes
SHA-256: b6831cffbfddfdcee97e4f0f60aae76bde122d9a71f11b182d2278361de3c10f