Malicious PDF — malware analysis report

Static analysis result for SHA-256 154ecbd79fefeb85…

MALICIOUS

PDF

79.0 KB Created: 2021-09-09 03:45:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 5e2c4245eb88ca91b1ab70ae1d486092 SHA-1: 739e6f19bbcb59917a74814d0398dbbc05eaf442 SHA-256: 154ecbd79fefeb854cb702f26d73dd84ca8a6aea5f60d62e15ffbf86220b5b38
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6181

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://coretry.ru/uplcv?utm_term=clip+studio+paint+pro+manual+pdf PDF link annotation
    • https://markmont.eu/editor_uploads/system/files/zipow.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/4c32660b00dd9dd208988e35987d198e/21906026545.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/gusewin.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/16951942161.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/5118373316132696367ceb.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/62156583742.pdfIn PDF document text
    • http://bhartiyambeohari.in/userfiles/file/90620139781.pdfIn PDF document text
    • http://sanphamhanquocymy.com/uploads/files/kosexiporilegonikudizone.pdfIn PDF document text
    • https://tndvn.com/js/ckfinder/userfiles/files/26287271355.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/mujegosiriju.pdfIn PDF document text
    • http://cen7dias.es/userfiles/files/xojawobikoxu.pdfIn PDF document text
    • http://afslab.asia/upload/files/2118467997.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394bffcaf99---tesusamepobiluj.pdfIn PDF document text
    • http://citty.org/images/uploads/file/61594745506.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161374090243d4---89203986546.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161363512a2b81---gekixalalodoxugepibu.pdfIn PDF document text
    • http://heaig.org/editor/ckfinder/userfiles/files/jatanuzapupel.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613034395330a---xixakugizexeza.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/duxikara.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/abf2da932c22ea37bc895b1941554d89/masoxoragelofokixewetas.pdfIn PDF document text
    • http://espokebar.com/uploads/files/dojekov.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/11997ff97f3f58771f3da0eb08df2eda/53617863532.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/7a5cf0dfd5de14af18897875b7c59048/sozekax.pdfIn PDF document text
    • https://www.zochrot.org/ckfinder/userfiles/files/radurenukanesukijazukaf.pdfIn PDF document text
    • https://jocafoto.com/fotos/file/kifuluw.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_off0000dc1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1D 10660 bytes
SHA-256: 561d6c29e41095552b778adeef780a086d17ab56009699ae2c155c7f461a89c7
font_01_sfnt_off0000f47e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C90 18284 bytes
SHA-256: 82180b6ef43e9d8b04dec0f79010b38a63c4cf9641b4ac05e58fdf6eabd77416