Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5e81d6bfb10a8d8…

MALICIOUS

PDF

81.5 KB Created: 2021-08-21 10:13:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8c0f0671d191d9350bbec2b110fbdcfa SHA-1: baf0ce23d876ad5f2909213598459778a459cf8a SHA-256: f5e81d6bfb10a8d8e3e82b0a6796c52fc710e2974b06e5a2a147e34d45dbb126
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised or disposable hosting domains, suggesting a phishing or malware distribution scheme. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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://aj-freight.com/ckfinder/userfiles/files/89893448832.pdf In PDF document text
    • http://infosierra.es/images/editor/sikoxasemezonepolak.pdfIn PDF document text
    • http://lesen-und-schenken.de/userfiles/files/10445229443.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610d7fa733573---repuwutitux.pdfIn PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/depupejawurufowevezugu.pdfIn PDF document text
    • https://nada70.org/userfiles/file/97069752715.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4cefcd7e0---wukazinixewujir.pdfIn PDF document text
    • http://tomaszskiba.com/userfiles/file/meberovu.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b44af1663---88362481075.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/vfojjebb18mdvvn3etmcuqam1m/deganigigibi.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1611d09ad3ba67---94473913942.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/pobutekemavekumo.pdfIn PDF document text
    • https://heks-tech.com/app/webroot/userfiles/files/bosujovofa.pdfIn PDF document text
    • http://www.tecs4.com/intranet/ckfinder/userfiles/files/tazitadusotimili.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161083f45ab82c---94498759818.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/b8ff5e8edf1018983aff48119dd9511e/leponotejube.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0f37929e76---fedalor.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210803_190323_125.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/o061g7ob008jhg3l42khqt0h2o/89049815159.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/tebilesefopopame.pdfIn PDF document text
    • http://branpc.in/ckfinder/userfiles/files/65401249843.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/sawiwugarupewobiniziba.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/bejexuvewizimabure.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/16082067d23085---51229353443.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f95c313cf6a---99454350072.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=bee+swarm+simulator+hack+script+download+2021PDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1AF 11404 bytes
SHA-256: 25f46a8a136d1f1634321dd422fdc45260c3ed3dcb45c5ee5e0009f8c8385651
font_01_sfnt_off0000dc91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC91 16500 bytes
SHA-256: f514a57a132e19e072fbe500c0559cce0e01b13f68d95ff1a362f0e19e544fbd
font_02_sfnt_off0000f331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF331 17380 bytes
SHA-256: 7364ef74ae6fe626daa69fdc4628936d90e8d5bb3ede54d249c3de810c5b108b
font_03_sfnt_off00011f86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1