Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b8fc2cac4c38991…

MALICIOUS

PDF

75.7 KB Created: 2021-08-12 17:14:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 56531473cce5621433f17fd7ea8b3d2a SHA-1: d8c7b9c5ebc5dac384e410d9d232b76e78206abf SHA-256: 5b8fc2cac4c389910bd9800a44891911a698e2f88c943fc506dae28406581e5a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://inwebjor.ru/uplcv?utm_term=emmet+fox+pdf+espa%C3%B1ol PDF link annotation
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16087b294ed9ce---sesovofiparutazeluvaj.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160980cb12d581---75964131865.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/biwepuvekuk.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/wunakodegux.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/hk7464ii5d8oufo8d3t6tif01u/jomawogile.pdfIn PDF document text
    • https://szud94.hu/img/sajatfile/files/wulutufuriwimeg.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-5-22/20210522173847191907.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/ca0eb85019647a4233b72ebe55cef41f/katusisoguga.pdfIn PDF document text
    • http://dotykbylinky.sk/_subory/subory/wolinemimame.pdfIn PDF document text
    • http://siamsnail.com/media/userfiles/files/badexepi.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/fejanudatuwomiwa.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/kidagu.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/10709039569.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/2235072629.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/46275515492.pdfIn PDF document text
    • http://edgecs.net/documents/60907271553.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/43314040714.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/892a5a38f6ebd052fe0611159103bf8d/siwarodetovu.pdfIn PDF document text
    • http://abpaluso.com/upload/file/41887158679.pdfIn PDF document text
    • https://samowar.me/upload/file/74418473150.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3dfa70db08---68541582483.pdfIn PDF document text
    • http://perfecturology.cafe24.com/upload/editor/imagefile/61799431321.pdfIn PDF document text
    • 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_off0000c1a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B6 17524 bytes
SHA-256: d347f36c2cda5199ab8eaaa4a7eeb5dcdde1a23a2b2aba0b7d95dd61ed93b41f
font_02_sfnt_off00010683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10683 10652 bytes
SHA-256: a52ffcaad4f5110c34eaeacd7cbab71b60f76f6aeb0e037920809eee14a224b6