Malicious PDF — malware analysis report

Static analysis result for SHA-256 e831fd4b685f4d05…

MALICIOUS

PDF

74.8 KB Created: 2021-06-25 19:25:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4a722f004d04fb2dab2eaafa05c28cfa SHA-1: 5ca84001259401b6fde6f67f38fd432415aa4ba6 SHA-256: e831fd4b685f4d05bd5e2c421cf724e681607d3ec8a00c25333f16f1a4513090
156 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs that form a link farm, pointing to various domains, many of which appear to be compromised or disposable hosting. The primary function seems to be directing users to these external sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://abofahed.com/userfiles/file/25027630480.pdf
    • http://wo-kop.pl/userfiles/file/91255795383.pdf
    • http://alexlunacoach.com/img/editor/file/24425274998.pdf
    • http://abwferrellpkwy.com/uploads/files/47836496206.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/ec361a56c1fd745a866aca4c8386d517/nitikotulowupagaw.pdf
    • http://writtenmail.com/upload_images/file/nixevumajosujasuxagid.pdf
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/16074f820c03da---98670297790.pdf
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/a6c9aeea9df4b387839870cac3c37041/82656914251.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0e473a962---31717615722.pdf
    • http://texmet.pl/userimages/file/71109014364.pdf
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/g2tc5hl9qe9cvguif40lbuha8p/nojirobuxif.pdf
    • http://itkaufmann.com/images/fckimages/file/vemuxutawuk.pdf
    • http://yoron.net/up/files/jelinuputu.pdf
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/d048379569d45fe6df1fe402cb8600c2/bipogo.pdf
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606dbcd363be5---62810739037.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bf52e5cb62b---gagusijivisozi.pdf
    • http://metallpress.ru/files/57000442606.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/71335249a3cbb3db74c5f687b3ba3888/59705590015.pdf
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/pl553r5p5d3cn34ov534b2ld70/20922222396.pdf
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160834af2c5f81---96769277369.pdf
    • http://bwc.lt/i/pusevibukujewijosofe.pdf
    • https://abofahed.com/userfiles/file/gulumexunejitiv.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=total+english+10+icse+morning+star+answers
    • 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_off0000c0b1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B1 16792 bytes
font_01_sfnt_off0000d8c8.bin
fc9e78a57456707fdcc7dec988f73b0401a1731ccbccba3fcc93598cc58393ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C8 10900 bytes
font_02_sfnt_off0000f1e8.bin
6d237477f0ae6c72ec810a87fec6e3e73b41047e93e95b5089035b4954c03c08
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E8 16848 bytes