Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3960e841fe72a78…

MALICIOUS

PDF

69.9 KB Created: 2021-09-29 09:32:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a2e1f6c12a64510e4589804800b3c906 SHA-1: e1250a6683b74d4060035195613d3b90058e2903 SHA-256: b3960e841fe72a78885f27f0e749300d36f284bb468ef9b0f1ada62b049fcb4e
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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 https://wastran.ru/uplcv?utm_term=how+do+you+put+a+hex+on+someone PDF link annotation
    • https://hinaweb.com/upload/file/3955451221.pdfIn PDF document text
    • https://fulzugaskozpont.hu/files/zawebovika.pdfIn PDF document text
    • http://agriturismolionsfarm.it/userfiles/files/jigepivuvifigux.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/salanal.pdfIn PDF document text
    • http://decaiyun.com/upload/file/210907151940934311v0b4cpbu1w37.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ed07cad34---24690673930.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/78945782926.pdfIn PDF document text
    • http://aqua4you.hu/userfiles/file/dejiduvipikogewanapoxe.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/161362ce3dca77---21474465258.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16141e5375b772---tukizub.pdfIn PDF document text
    • http://preiswerte-unterkunft-papenburg.de/mediapool/41990500581.pdfIn PDF document text
    • http://gardens-spa.com/user_pict/file/revamawivukigoxepajudekiw.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/magularufor.pdfIn PDF document text
    • http://didaconcept.com/admin/fckeditor/file/10886922277.pdfIn PDF document text
    • http://bulmarconsult.com/files/8907404286.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/d8a3e58088f3c6fd2129dee903f23fdd/19396995497.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/88066816042.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/nojusipavevuwin.pdfIn PDF document text
    • https://lp-tracking.com/userfiles/file/18343475877.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/83389507450.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1614e3c5795af1---guwikagexelovowetuguga.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/wifidofek.pdfIn PDF document text
    • http://ad.ditroinfotech.com/laportal/ckeditor-ckfinder-integration/uploads/files/32235287173.pdfIn PDF document text
    • 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_off0000b101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB101 10812 bytes
SHA-256: 17d49391155b33880d753b8406e6c08faccebec1162ea90d80fad7d797f830b4
font_01_sfnt_off0000c9d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e1eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1EB 15248 bytes
SHA-256: e7a7c4871a9b31615a812902e05371e03f8216301f77057b0af25fa3162e369c