Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab51e00d58a7d2d7…

MALICIOUS

PDF

70.4 KB Created: 2021-09-16 05:43:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f0bc9f201a56192927075b8a8afa669f SHA-1: 5650c68447e2a9c11a11884bb6420e800f146ad9 SHA-256: ab51e00d58a7d2d7ec4bb374eaa5809df75f672050c9afa2600dac3194c87b91
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://smidgel.ru/uplcv?utm_term=samorost+3+apk PDF link annotation
    • http://aotwresort.org/ckfinder/userfiles/files/biwoponuwas.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16141196bf368e---50325695201.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/66843217237.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b637cf1a52---16290260233.pdfIn PDF document text
    • http://www.optimizecost.com/admin/ficheros_fckedit_subidos/58040989757.pdfIn PDF document text
    • https://iasvn.org/Images_upload/files/26170678526.pdfIn PDF document text
    • http://eortak.com/img/fck_temp/file/9651928103.pdfIn PDF document text
    • http://rebeccafantarchitetto.it/userfiles/files/rujiribesawiwezalas.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/29546254789.pdfIn PDF document text
    • http://cp-1.ru/userfiles/files/pujapulapabupigofep.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614224db64136---43593851755.pdfIn PDF document text
    • https://www.terraton.com.my/ckfinder/userfiles/files/zazijakomo.pdfIn PDF document text
    • https://matfplayer.com/calisma2/files/uploads/37240106149.pdfIn PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/lakerexufukof.pdfIn PDF document text
    • https://proetcontra.hu/userfiles/file/sokem.pdfIn PDF document text
    • http://leylatoprak.com/userfiles/file/vofutegekikiwojobofezor.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/kavoxox.pdfIn PDF document text
    • https://tomas-music.com/contents/files/76404491959.pdfIn PDF document text
    • https://dobski.pl/userfiles/file/57958390790.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161385d985199b---nigowosasosafikixigune.pdfIn PDF document text
    • https://signatureshreyas.in/userfiles/file/98959972750.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/84885918627.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/161429a718737a---66798435323.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_off0000b171.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB171 10380 bytes
SHA-256: c14b563c40f2b1a4ff4cf48a8e92602e93cbadb9e3a8caa0614af695b225d9f3
font_01_sfnt_off0000c8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8EF 17260 bytes
SHA-256: c413e9458c9217e1507c855e2a6a9b7136eac7cb3e7630398d4f74b32be7b29b
font_02_sfnt_off0000f443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF443 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1