Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7faf21149324b9e…

MALICIOUS

PDF

78.1 KB Created: 2021-06-30 18:42:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ff3434b35e617c8b46db1abe98978e6d SHA-1: 512d17eab22ab96f824e3430a4e76abc2cb94710 SHA-256: c7faf21149324b9e305e9c852ec7d53d4d7752775d58c4890cf9e116d524b4da
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to compromised WordPress upload storage, suggesting an attempt to distribute further malicious content. The presence of embedded URLs and the 'download button' heuristic indicate a lure to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=if+i+born+in+1999+what+is+my+age
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160782a00e67d6---tozoker.pdf
    • http://www.radio-kum.si/data/files/lonetafi.pdf
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/ff40070548f330ba8448ca42d11251a4/felajiretoguweb.pdf
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/13371551217.pdf
    • http://maslag.eu/userfiles/file/71282214875.pdf
    • http://www.dean-cpa.com/files/adminpic/file/nababo.pdf
    • https://red-adlay.com/upload/files/tomogumi.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16072fb4738098---99385192664.pdf
    • http://szao-spb.ru/images/news/file/pepuse.pdf
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/0373ba82ba06b8ccd5310f0216701e22/rodarujufidotozuwapediba.pdf
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/3bc28e0b603ad200844f8e20c67d2143/751385308.pdf
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/jckt4mpa3q5iesorld75dikor6/leriwivebelu.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087a556bdbbc---tixarepafisojetibusekawo.pdf
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/83809ad86f125c0bef2bc7cfdb5ff117/39779676993.pdf
    • http://arcstema.com/userfiles/files/35911527494.pdf
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16092184b137dd---3703928508.pdf
    • http://adaviestransportltd.com/userfiles/file/48868171954.pdf
    • https://taevlingar.se/images/pages/file/42059647512.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc8b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8B 16792 bytes
font_01_sfnt_off0000e4a2.bin
cf7344f6f28bac2f8ca12e2d41fc6b8c70951b208e50893d1e2a3976fe83ecf8
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A2 11128 bytes
font_02_sfnt_off0000fe95.bin
74d2ec0b5dbfc04128709fa144865c2d42cf07ccd39e4bba1e1d5aa83e88eb91
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE95 17456 bytes