Malicious PDF — malware analysis report

Static analysis result for SHA-256 16c61abcd6676fcb…

MALICIOUS

PDF

71.6 KB Created: 2021-09-06 00:46:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: b714e8634a2d4b2949c22d74b7283d01 SHA-1: 9a78467a096368e6a6c95dd852eaa12af92a4ded SHA-256: 16c61abcd6676fcb7c934aa8659cd7cba90da404ec3a81b36b929c7ea36e6076
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to compromised WordPress upload directories, suggesting a phishing or malware distribution lure. The presence of numerous unknown URLs hosted on potentially disposable domains reinforces the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16128027d155fb---fedafukipukeve.pdf In PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/61884141979.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b754a5c163---69000353136.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/96818993055.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d8a655b3b3---18573028230.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/3b3873b84e77e98129bb0a19e7ab9171/56372372090.pdfIn PDF document text
    • http://cherryontop.pl/upload/fotki/file/91585650265.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/1bacdb2dcdb3314cff8fa541a3a4b135/77555572287.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/587f5c8e4e22e150408ea016026b253f/62307500295.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6398758ca5---21076108994.pdfIn PDF document text
    • http://samtle.net/ckupload/files/putezegusobawawoxu.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/54618418549.pdfIn PDF document text
    • https://watfordfairtrade.org/app/webroot/img/files/69294053977.pdfIn PDF document text
    • http://szyqjsj.com/UploadFile/file/20210815084355000.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/vapokogum.pdfIn PDF document text
    • https://aarushimukhwas.idealviews.com/userfiles/files/zunukamulug.pdfIn PDF document text
    • http://phayaotechno.com/UserFiles/File/38822561699.pdfIn PDF document text
    • http://udaybharat.in/ckfinder/userfiles/files/botanivajafibigozaborazar.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/67503942863.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/0r6vis94j2rfo1n28hqp6cvuu2/dinuwo.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/7dc1858d99eea32253b0f657aba052cb/golopifoxira.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/6emmn7krhe12rbve9pmlo25rqe/13119764032.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c41a19d718c---sukojipubebexe.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/tasolojega.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=mpeg+file+format+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_off0000b71f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB71F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF31 16352 bytes
SHA-256: a696da5e24ec6a315ded6c826faf88a2d643b2ac3cc770620dd8ee7a90cf775c
font_02_sfnt_off0000f923.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF923 10560 bytes
SHA-256: ba57ded5dac5e915107ea5495bca40e4bbea735d7afa54a525c2d5b3056ae651