Malicious PDF — malware analysis report

Static analysis result for SHA-256 aea85b9d325d149d…

MALICIOUS

PDF

80.4 KB Created: 2021-09-03 20:34:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ef60717861446788fbabbdc775e0e258 SHA-1: cffedb78d17eec582924712ff77c46a685aa7553 SHA-256: aea85b9d325d149d35378d774b76fdf8d83fa5486846449b30c7d5c781858caa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous external links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier further support its malicious nature. The file's structure and numerous URLs suggest it is intended to lure users to external sites, likely for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5932

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
  • 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://inwebjor.ru/uplcv?utm_term=les+homonymes+et+les+paronymes+exercices+pdf PDF link annotation
    • https://e-uchebnici.com/img/file/10922393572.pdfIn PDF document text
    • https://livewireeventz.com/userfiles/file/zateluderegi.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/18294900928.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/88721172586.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcf3d107161---74019100430.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/4963231767.pdfIn PDF document text
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/160914237e7861---66059248386.pdfIn PDF document text
    • http://hotstamping.pl/files/file/33616567113.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/e86d820dfd629cb77b7dc2c376ac8134/gozasewewamuvejiwejepem.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16086dcc53fa7a---49222580482.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/xaravitemorilax.pdfIn PDF document text
    • http://liffeyartefacts.com/fckimagefile/file/jukosovimitiwe.pdfIn PDF document text
    • https://paklya.su/design/img/upload/file/11534829292.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/fu7endlefdfe9egm2ckg0a7hpv/rewokerozapimebedem.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/boliwivolozudusewefas.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/18216690112.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/lijizazufumuwo.pdfIn PDF document text
    • https://mma-montessori.com/admin/ckfinder/userfiles/files/pojeposufeguv.pdfIn PDF document text
    • http://elturo.ru/img/upload/files/giluzexerukafufijom.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/rapalavabejavibib.pdfIn PDF document text
    • https://samoinstitute.mn/uploads/assets/file/gunitulegezidanuk.pdfIn PDF document text
    • http://dd-eng.com/files/files/33916876728.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a447a29a909---27139281734.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/40807589754.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_off0000dc00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC00 11060 bytes
SHA-256: f691651edbb0d743b034bab0fae3037a1f381918ee077915b522dfafce8d19d4
font_01_sfnt_off0000f599.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF599 20292 bytes
SHA-256: b28cc7c9a6e6697b9de982fec1bfc7e9816f450428accbc4bbb54ed0472efc28
font_02_sfnt_off00012855.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12855 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1