Malicious PDF — malware analysis report

Static analysis result for SHA-256 8525cb054b79abcb…

MALICIOUS

PDF

72.1 KB Created: 2021-09-26 13:03:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 54ec4537d57fde27f16b897afe1ef871 SHA-1: 9d5bb08e65bccad8f98331a18afd79e45c3eba01 SHA-256: 8525cb054b79abcb66d522aebddd155a2f7a67c481cfc741944a6245cb514313
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous external URIs and link farm patterns, indicating an attempt to redirect users to potentially harmful websites. The presence of compromised CMS upload links further suggests a malicious intent to host or distribute further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://ketchas.ru/uplcv?utm_term=adobe+rush+apk PDF link annotation
    • https://www.eos.org.eg/ckfinder/userfiles/files/vadilotiwegikezoxada.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/778ce125847e22399119f3632a238f00/84736059636.pdfIn PDF document text
    • http://mariondhuique-mayer.com/data/file/rebavov.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/semigepagub.pdfIn PDF document text
    • https://airxps.com/userfiles/files/savejoxususalo.pdfIn PDF document text
    • http://underbutter.cz/download/foto/54296650118.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/kuzobonimigelojiweviv.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/161313e82d342a---65560984791.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/tanatatulasibivaso.pdfIn PDF document text
    • http://cuanhomkinhtoanthang.com/media/file/69634429836.pdfIn PDF document text
    • https://actsonics.com/uploads/files/202109241647193126.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/54921603939.pdfIn PDF document text
    • http://permagnet.com/upload_files/file/210913130604862017079jyd.pdfIn PDF document text
    • http://machin.kr/userData/board/file/16274562974.pdfIn PDF document text
    • http://samocvet.org/foto/ck/files/43936452889.pdfIn PDF document text
    • http://ratchadatitan.com/UserFiles/File/lizetikotadapasamu.pdfIn PDF document text
    • http://sandiego.songhakbbq.com/uploads/files/45294456431.pdfIn PDF document text
    • https://autoskola-scp.com/files/pinawazuwufotegom.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/51211791916.pdfIn PDF document text
    • https://nyig.com/files/file/49360900811.pdfIn PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/26965158038.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/9726035852.pdfIn PDF document text
    • http://starfishdowney.com/uploads/files/49209717419.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/regit.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/3341c359d56e821b0f0f9292d736214d/68839136071.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_off0000b3c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3C3 18596 bytes
SHA-256: 09a8314942812618fd44792a34cd0464fe5b71bba4036e7d95b229513bcb1f3a
font_01_sfnt_off0000e39c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE39C 10464 bytes
SHA-256: 8e3d308efcb762573b13eff9429003e225ab6e0047ebcfc9ccb8143bed3bfe82
font_02_sfnt_off0000fb48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1