Malicious PDF — malware analysis report

Static analysis result for SHA-256 a331659acebee00a…

MALICIOUS

PDF

83.8 KB Created: 2021-08-30 12:20:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f44588c1ddf66e04bd91d07e0e7b8d30 SHA-1: 97ea95336d613f6d44d317f450ef174b127bbe3a SHA-256: a331659acebee00afe0cc4bd61dca712a36786596d121db1d6ec19e69d0766d0
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to numerous URLs, several of which are hosted on compromised WordPress sites or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the URL analysis and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://postelezmasivu-zlin.cz/ckfinder/userfiles/files/dazupekegixolitesujudofib.pdf In PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/61715645514.pdfIn PDF document text
    • http://malbreil.com/userfiles/file/26926449612.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a64e784abe2---susub.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/49595827708.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ba3a112b853---zuvikiwogapanabi.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/35423527369.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/59445914347.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/c17ba3962ab5b4284edf0f509cf5252b/53202897786.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/88558223476.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/8a27cc80355f4d866ffd9517ea7a788b/gebebiguzugonusojiwexiw.pdfIn PDF document text
    • http://vitajeans.com/ckfinder/userfiles/files/sumapulagenopaminumavut.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/46ea7998e026f79e8919bea4814e6748/98208906941.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/mofolezad.pdfIn PDF document text
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/fbbedee34ff0d2d5ac9ebcd8332dd17c/tubosuravolederikawi.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/povodofexod.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16098883f68491---polijuxosepef.pdfIn PDF document text
    • http://fullcolorspandoeken.nl/userfiles/file/97367325004.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/62138536709.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/92481202415.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=how+to+write+a+lab+manualPDF 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_off0000e657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE657 10416 bytes
SHA-256: 6352f4905c57fb9e37b0565bb245f1807558238fd283eaafb073d3a24adb3792
font_01_sfnt_off0000fddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDDF 16880 bytes
SHA-256: 4d0c45e465c1f54a58521aff78063cf7bd09c40f67404c237df4b917b70bd488
font_02_sfnt_off0001291b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1291B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1