Malicious PDF — malware analysis report

Static analysis result for SHA-256 b77f9e5171369eac…

MALICIOUS

PDF

83.7 KB Created: 2021-09-22 21:14:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e7421b29af76ba44d0e1f9acc7bb09c1 SHA-1: 58d7a0e69864490e89820367c03ce269fc0e41cf SHA-256: b77f9e5171369eacc4a954aed377b787da6dfaef639243d29a0132f8793ae113
176 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress upload directories and other disposable hosting sites. The document body is heavily obfuscated, but the presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicate a strong likelihood of phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://www.mab-solutions.fr/upload/file/70662749556.pdf In PDF document text
    • https://soudureornementalelauziere.com/upload/editor/file/89602812749.pdfIn PDF document text
    • http://st-ark.it/userfiles/files/77153543867.pdfIn PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/52673142529.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/364d9dr8tliea4uh8eii34rrs0/533177187.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/dazifidedosepagapafuropek.pdfIn PDF document text
    • http://cocoabuterol.com/upload/files/wipemidutixesorosesog.pdfIn PDF document text
    • https://ingatlansos.hu/images/userfiles/file/99882206618.pdfIn PDF document text
    • http://ccsctda.com/ckfinder/userfiles/files/20210923_001256.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/5bduqrjqsge0b9aaiiidimubvj/penekarutexerozin.pdfIn PDF document text
    • http://ilyxrace.com/userfiles/files/90062391295.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/bolanivo.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/19419513562.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161495f0907558---10895451786.pdfIn PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/pilewetas.pdfIn PDF document text
    • https://badeluxe.com/userfiles/files/javowosofudakodoxatasigow.pdfIn PDF document text
    • http://abwva.com/uploads/files/tekaxejewigonemol.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/gcmplmtum7qfpuqd5i2l3r0mp1/82320088224.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/zuwatiwabewejatisoju.pdfIn PDF document text
    • http://www.blueoak.fr/image/file/40464791714.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/31900650982.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/17b16f5ecce8fe997c0fc4a83a70f0ac/10907976745.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=the+ecg+made+easy+pdf+free+downloadPDF 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_off0000e131.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE131 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f948.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF948 11040 bytes
SHA-256: 7b0de86811d2c160710a9bd84e00e51c4fc9fa0d7c6561c48a2a4e9c9d2c2547
font_02_sfnt_off000112a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112A5 17628 bytes
SHA-256: f7dbdaa20231defa70d1e8a8763b36718cce0c3eddb4179e97500979a94f3ace