Malicious PDF — malware analysis report

Static analysis result for SHA-256 44a18115c90e4952…

MALICIOUS

PDF

80.8 KB Created: 2021-07-22 20:44:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7d36d5e6b12aa358b6d05278614e0aae SHA-1: 93988967623297e296b8198d67fa807ae7d32e2f SHA-256: 44a18115c90e4952d9c99849ae4dcee7cb49ac87e7dc108984f21e25672a5819
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier with high confidence. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. The presence of external URIs and the nature of the heuristics indicate an attempt to redirect users to malicious sites.

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.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607754897c418---wenuzalegetuwedexenetu.pdf In PDF document text
    • https://ppuhperspektywa.pl/files/edytor/file/50507003830.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/ece10ae107441692356bfcfec199c678/jorofobuloj.pdfIn PDF document text
    • http://diclenakliyat.com/userfiles/file/gudebujalabizosozobasexe.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/9f162983df1dd2e25d2ebaa1f7c066a2/87573909939.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/rokatalojom.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-4-29/20210429080213187907.pdfIn PDF document text
    • http://dchs1961.com/clients/871949/File/muderoxunorevijase.pdfIn PDF document text
    • http://standdominica.org/files/files/ferata.pdfIn PDF document text
    • https://wittnebel.dk/file/37529076954.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/24bdc3efa111209e1a5760997fa40d64/jojisuwigosudusikefusezex.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/4ljk9jda00sb1nu4l3qj98quj7/42613773783.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/56662837420.pdfIn PDF document text
    • https://nistd.in/userfiles/file/zukoro.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e377dd477---74908297149.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/29143394161.pdfIn PDF document text
    • http://jucal.es/images/file/dapimagenunalosopezuwosa.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/t4os15nu318ohgk6merqdulash/71246823567.pdfIn PDF document text
    • http://christopherspubandgrille.com/userfiles/files/dosurigobebuwonafo.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/37667430946.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/ad95eedf3c0fd28a27acad2cd808657b/58816566718.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/pajawexupak.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/1f02fdef06e43d729281fccc248d2877/sutok.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160839e2f77af8---sukumijakusek.pdfIn PDF document text
    • http://clubsahdianagalati.ro/upload/editor/file/savigiribewawaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=small+pdf+to+excel+converter+online+freePDF 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_off0000d6a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A9 10856 bytes
SHA-256: 91c8aa817a5a4d1d1c9fb08f619412b6f0def0ff1e44e0b8c36dde47a7283bdc
font_01_sfnt_off0000efb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB8 18372 bytes
SHA-256: 035c30700a92cb3a47ad14b7997a31c68475aa09510127c7560fe3d7a8052f5c
font_02_sfnt_off00011d6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1