Malicious PDF — malware analysis report

Static analysis result for SHA-256 527888ace80bb635…

MALICIOUS

PDF

81.1 KB Created: 2021-07-18 12:33:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 3c132f70ed993ed03f0cc8f72291dbaa SHA-1: f157592994fb9e5ff4acf120ba139998bd1138c2 SHA-256: 527888ace80bb6353a4a5d8c02d6ac6ff5e2454c53241ed8462840b4c78f72c1
184 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains multiple heuristics indicating it is a link farm hosted on compromised CMS upload storage, likely intended to host malicious files. The presence of a 'download button' lure and a callback phishing pretext further supports a malicious intent to trick users into downloading further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160eca12868cfe---60914116392.pdf In PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/k47shf265r314m2373i6mjd7os/68203437334.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ebb5c60e0---rokuwabesejow.pdfIn PDF document text
    • https://wrd13.com/force/file/vototoxobanut.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/65b26271202ad2cdb3e2836874df07e2/purivisopixefalaketedazu.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/s7gcvom897a6mmnut5cpar4m11/31223301077.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/a5bfdb7de935c0b55440f58379e901e9/zikirozikatewovuwemutos.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/rd3reo082373h3fj9p3jd2t3c8/90555608239.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/66108755860.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607180f2ce255---ditim.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/ba6578f8633c5aaaeae574a5894938c7/8681977876.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c74ff2aad6a---44412327771.pdfIn PDF document text
    • http://cp-1.ru/userfiles/files/nefesume.pdfIn PDF document text
    • https://reparation-mobile.net/userfiles/file/22842414271.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a4df56b0d1d---4352265218.pdfIn PDF document text
    • http://mariopresto.pl/userfiles/file/61649290218.pdfIn PDF document text
    • http://greenbrier101.com/userimages/18767910234.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/sanafujukenage.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608561c6d048c---27316254587.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/vipabetufamumef.pdfIn PDF document text
    • https://nhachoxebus.com/upload/fck/file/57540925632.pdfIn PDF document text
    • http://www.gabrielamaciel.net/images/content/file/36621015134.pdfIn PDF document text
    • http://drivingschool-brno.eu/files/kumamosufikotezedet.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/p4am6igm041rd45chb4gkt3c0u/7273370042.pdfIn PDF document text
    • http://pvhs1980reunion.com/clients/e/e5/e5e9f74eb83211af097e98bf68d59c4c/File/37567787529.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=page+separate+pdfPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/edae6809e8ddbaa02bc65a21a63b75ea/ronat.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_off0000dab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB1 10312 bytes
SHA-256: 85176b80474d8f4f7f1cffe8d947b7e0b58fbd5e4267a748483e4025550d26ed
font_01_sfnt_off0000f1e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109F7 17460 bytes
SHA-256: 751c97022c00e856cfaded47dc87a47c7bfd386492bd12aa3b7de364b0b015ec