Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55c3c7b162e5a4b…

MALICIOUS

PDF

88.3 KB Created: 2021-07-04 01:45:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: a538ce4f7b5765243bd794bb4e0604eb SHA-1: 6afc7710bb335c8b4753f9c1b8168a07f01fdbc4 SHA-256: a55c3c7b162e5a4bdf8159fce25c1e7794aa251b494ca4c13975e4641606f60a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a74f4dc1d---11870751423.pdf In PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/fbe90c2b0e610fa2ab84e74245e42e5c/zikemawasonivukabekafoxe.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b4ad1b6dc---furer.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/51644631755.pdfIn PDF document text
    • http://cloverdiamond.com/file/lejokuworefe.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607887fdd162a---sigosotowa.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/3517e567bc4c575003d44c353d05878e/zepumigulexetonom.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070abf23759e---59860982537.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/16084bd25edd24---litozukok.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d362a24c123---62373109872.pdfIn PDF document text
    • http://valeneighbors.com/userimages/24737914553.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/1c8d4cd5a222f58ce35d955b76bb4927/56623631620.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d77b0402931---97909235860.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a50c3ca4393---62139456920.pdfIn PDF document text
    • http://aweibel.com/Photo/file/5020441093.pdfIn PDF document text
    • http://starlightcelebre.com/clients/4/43/43e9139217482d7666ce300faf566241/File/zotunemeru.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c252cb83cc---85410221781.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202105030032192812.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/e628be726ad5d3e91bf29b4fcf6bd1bf/wiramebutodajusowezexiju.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/5964bfe5940e175c99d3b3680d7e6444/zuzuwilakavifotaruzenoxa.pdfIn PDF document text
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a17f6069a9---fuvegetejinikirizipazazop.pdfIn PDF document text
    • http://csim.jp/ckeditor/uploads/files/48598813081.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160adce5878621---junelaga.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab4b7894ba---80972124082.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=sentences+if+clause+type+1PDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/7244cc149ede0e5fb773c830b300e55a/somofosonodimuropewiv.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_off0000ee3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3E 23176 bytes
SHA-256: 3090f5d4fdc5315cdde922d254c02f2a4ab24b46e99a82c670ece4af828922b6
font_01_sfnt_off000121b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000139cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139CC 10596 bytes
SHA-256: a5d200581c34d453fe20aeb0435121db300e09a2339fa20a67a2daa996b835e7