Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a552eec10382a1c…

MALICIOUS

PDF

66.4 KB Created: 2021-09-15 10:00:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 52b40ee68d52629b395c873a1c79b4d6 SHA-1: 8f97dcd1fd2d6d64badc60a38c2825cfa9d24baa SHA-256: 4a552eec10382a1c3cfe17a360061b0f1612d982c2609c020dd52e0a11dadf27
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and a large number of external links, many hosted on compromised WordPress sites or disposable domains, suggesting a phishing or malware distribution campaign. The embedded JavaScript likely facilitates the execution of malicious actions or redirects the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8010

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://ketchas.ru/uplcv?utm_term=android+emoji+creator PDF link annotation
    • http://apart1day.ru/file/lifelunikinemexevorafanek.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/56046bca6dfc2eb91c63896905aeb9aa/maxuvetixik.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/sikurisotokupaf.pdfIn PDF document text
    • http://hb-hospital.com/file_upload/fck_upfile/file/36711375435.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/hged44u5vdhsgvnf6pmru8ku00/3288601705.pdfIn PDF document text
    • http://phuongsen.com/img-chamthi/files/96867865658.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/xuwemaduxudesuj.pdfIn PDF document text
    • http://lexus-custom.com/js/upload/files/vaxebijasuxina.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/wibofeledajorizumu.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/45743388292.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/56733397572.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/943f3dfd4d2f693a226e5b8734a6cb46/4616853931.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210902205508275.pdfIn PDF document text
    • http://panda-es.tokyo/yamituki-n/uploads/files/96042966060.pdfIn PDF document text
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/temaxidukivesarides.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/nukebo.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161350a95b82d2---38513178258.pdfIn PDF document text
    • http://king-pro.com/userfiles/files/zonusudisazopusexejuli.pdfIn PDF document text
    • http://hstechno.com/userData/ebizro_board/file/wifevimovagotimilekaze.pdfIn PDF document text
    • http://cavusofis.com/images_upload/files/semisizuludojutunawog.pdfIn PDF document text
    • http://thuduchouse.vn/pics/file/devibetafugamumameb.pdfIn PDF document text
    • http://fosterfreezesantarosa.com/uploads/files/50738433184.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138eb210e2ff---veretukukupamuga.pdfIn 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_off0000b581.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB581 10428 bytes
SHA-256: ceed724664977ec0d9cad10c6a93ed5ba68b09748dd5589803399752bfcdf482
font_01_sfnt_off0000cd16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e528.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE528 14352 bytes
SHA-256: f3fb868fc6c4f3ec2216cbed4b4a89a45c209a2b028e79bc3341a03c5f6445fa