Malicious PDF — malware analysis report

Static analysis result for SHA-256 a31a54b0090b007c…

MALICIOUS

PDF

131.1 KB Created: 2021-07-31 01:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a5493a3b0c545f2217a738233211fb5d SHA-1: a2865d85476dc90156b8bf1efa30437f87df3a26 SHA-256: a31a54b0090b007c8f43a5cf4777941e395f75afab3556525f2c11ed15b01412
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to distribute further malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to create a non-clustered link farm on disposable hosting, suggesting a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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 http://beiwendq.com/userfiles/file/gixafixavuto.pdf In PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/e89903eaa039c79881ec7b9cc8f11cac/fudokovafewipekatozudap.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/fh04ibvb56kg59p1en3rrh630e/38601587811.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210728103835_5wet12.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a8213c5d1---rarexatinolazejijikuxen.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/48153997795.pdfIn PDF document text
    • http://brlairport.com/images/file/44493502230.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/64235940291.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/b0e6543876c989fa94e1dadc7577230d/79027828372.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/6a583ed41e7cd807409e41b5f8e85d19/tusaxumewef.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160974e458be15---7023598973.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/96ce673f83cf92a0bf12313c039de124/xodewotapuvopizo.pdfIn PDF document text
    • http://kotolantopeni.cz/file/44275742671.pdfIn PDF document text
    • http://rltclassof1970.com/clients/8/8f/8ff9f19c840b982a6efda18ba8bb483c/File/36671680925.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/95170860801.pdfIn PDF document text
    • http://teaandtiarasottawa.org/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/velixojixenodojesibeluje.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210519065122.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/34682ee6b67bafafdcfe412320360167/96745303382.pdfIn PDF document text
    • http://sdes.in/uploads/69740960895.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072e566b6ff8---bizoramugaxibanovutawo.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c4f60df847---difoxuduvapuzoz.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/f0f851mpuubd6gqfge6viro3cu/93787392443.pdfIn PDF document text
    • https://ive-cal.it/file/dobufavaruve.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/tiseg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+samsung+tab+3+rootPDF link annotation
    • 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_off00019988.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19988 10668 bytes
SHA-256: 911606e8f7cbb93214af049c16e91ae25d9cb1f30b46e6e023fcb1873ca987df
font_01_sfnt_off0001b210.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B210 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001ca22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CA22 20552 bytes
SHA-256: 45946a1456f7933fea4224de91efaf32fbc906518876e97ffcd48001cda16bae