Malicious PDF — malware analysis report

Static analysis result for SHA-256 5273be1dcf5e7eb1…

MALICIOUS

PDF

88.9 KB Created: 2021-07-14 08:16:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f56f8385126213e3d838ed9e492e160d SHA-1: fb9ae07ee938004416507dd28d64477ad12f7548 SHA-256: 5273be1dcf5e7eb17d1b95d60938ace71ee19f4c1a0e9ceac69bc88360bbbd29
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document exhibits multiple indicators of malicious activity, including a high-risk heuristic for PDF links pointing to algorithmically-generated URLs and a security bypass instruction to disable antivirus software. The ML classifier strongly flagged this PDF as malicious, and ClamAV detected it as Pdf.Phishing.Trojan. The presence of numerous links to potentially compromised CMS uploads and disposable hosting suggests an attempt to distribute a secondary payload or phishing content. No scripts were extracted from this sample, but the overall pattern indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 9

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078a617a2b0d---xoxupigamitekexa.pdf
    • http://richmediahouse.com/admin/uploads/file/pugagegotiwubobiwobumat.pdf
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a463d4daee---palalezilajofovi.pdf
    • https://karpzbeldowa.pl/uploads/userfiles/files/57173349954.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/obhkf7e6vpptdgc02sos93h359/jenovadaturirulodog.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a88f314858e.pdf
    • http://linkipt.com/_UploadEditor/files/fudixalarewirurokibenupu.pdf
    • http://immodraft.nrw/images/architekten_agentur_images_/file/74732147993.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc9171060e---dexikilametiva.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/eijdtrv89q9uv81cardc0l873c/40936643671.pdf
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aec91330ac5---45081997791.pdf
    • http://ozdoby-betonowe21.pl/Upload/file/32141459861.pdf
    • http://benefielddarrenfordhicksunited.com/clients/2/21/2186b72972973349411f8b90e6071e14/File/winon.pdf
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/6c76b1fa04ecd620fe28ca52fbf48241/73223141039.pdf
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/jowilonarexuzufaporex.pdf
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609744605d4d9---1861834613.pdf
    • http://www.brickchamber.com/ckfinder/userfiles/files/lafavipeg.pdf
    • http://bioterapiazabiegi.pl/obrazy/file/27182780201.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/bkl2m9mpg7vpbs1mj8re75fhb9/15670103683.pdf
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160beddf409bf9---26344856579.pdf
    • https://immobilgold.com/file/95975058004.pdf
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/95438908305.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=assassin%27s+creed+3+remastered+torrent
    • 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_off0000f362.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF362 16792 bytes
font_01_sfnt_off00010b79.bin
32fe617e46ffa8e77852326b3be71c751d6b87c44811dd16f3a9aeaa3112a5fd
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B79 10672 bytes
font_02_sfnt_off00012406.bin
7b1196b627950a965182191e4647251b300ca4daba4905cf6c82492410c1bc8f
pdf-font-stream PDF embedded font (sfnt) at offset 0x12406 18356 bytes