Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1de1aab45c9a4a2…

MALICIOUS

PDF

97.3 KB Created: 2021-09-05 22:09:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4b8d1518b2b16449d89bb0083ba356a2 SHA-1: 16cf38cb5d74f44fa80da6b9a62b88752a206e6d SHA-256: a1de1aab45c9a4a28cae0b111cde4e358b1451dd7f02e25cc3ffd261a5de4e70
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, indicating a link farm designed to redirect users. The document body is heavily obfuscated and appears to be non-readable content, further suggesting a malicious intent rather than legitimate document content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://au-zlato.sk/upload/files/petunofunulufoxuxevo.pdf In PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16117f2b67ddf0---fipuwojenamoburumejavaka.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e01ee527f0---xotemos.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/dixufosifuletiwaxabozo.pdfIn PDF document text
    • http://ud2-140.com/files/73172846963.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/30317232732.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/4987cb79b17de173c67acaf2d5ae7992/85245070175.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/a47cb6865abb5c7c08c9f8c996250430/kerijuxiw.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ac9f2a5d8ca---juzebalomorumaviz.pdfIn PDF document text
    • http://betaempire.com/uploads/userfiles/file/file/26639744938.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/b8c15378750515768df415b85f80a370/1941327818.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/puwovux.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608da53accee1---35316042130.pdfIn PDF document text
    • http://globaltruthmediagroup.com/clients/a/aa/aa8380eac451876ae6ab993bf3a720d6/File/konusu.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/42103084898.pdfIn PDF document text
    • http://trungnguyenjsc.vn/uploads/image/files/53456863257.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/12692218268.pdfIn PDF document text
    • http://raegcafe.com/uploads/files/23206925535.pdfIn PDF document text
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/5763c8988fb84b0b18b293599f6e0080/lofarenimakopasir.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bebcf936377---98309222291.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/14353506451.pdfIn PDF document text
    • http://hatowo.com/app/webroot/uploads/files/6686884465.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/gutanivaterik.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/75e90361d072d1c4b21e58572f8aed39/88788648225.pdfIn PDF document text
    • http://sushrutproctology.org/ckfinder/userfiles/files/66665378652.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=la+clemenza+di+tito+mozart+pdfPDF 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_off000115bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115BD 10628 bytes
SHA-256: 7a774ecda5dd3e49d99d8caee6ce42f455a68728444d03b3e4e9a11465658e2f
font_01_sfnt_off00012dff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DFF 18896 bytes
SHA-256: e93bd9306936f7b53677ad5cf8cf611a30fb87475b8635717ddbdd4b0fbc93d8
font_02_sfnt_off00015f60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F60 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1