Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5ca8d6ffa403ac8…

MALICIOUS

PDF

75.5 KB Created: 2021-09-18 07:56:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1088612245bb99ff5f744d16581ad726 SHA-1: 99abb59d61aedf03a657d1d853d66e1ca70199a0 SHA-256: b5ca8d6ffa403ac89ffb471b4c6d037f6d5833e5d6bdd8d93dcc2cbf3081abfd
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan-like behavior. It contains numerous URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting it's designed to redirect users to malicious sites. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure points to a link farm used for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://shinaval.ru/userfiles/file/ketikibuvevoxob.pdf
    • https://nocnepal.org.np/ckfinder/userfiles/files/jufekiwokatotodagelinel.pdf
    • http://tucholainfo.pl/userfiles/file/8634795990.pdf
    • https://eingangrad.ch/userfiles/files/kexoxolenov.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161450c44b2928---40887956519.pdf
    • https://jerseyshorepirates.com/userfiles/files/55689054876.pdf
    • http://kopdesign.nl/userfiles/file/27317220886.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5ce2b16c0---mozubifejiropa.pdf
    • http://111-orte.com/testarea/cwsCMSlight/media/files/nilofuwibip.pdf
    • http://placc.info/up_image/sewuxafojifuniletifo.pdf
    • https://ev-owners.jp/userfiles/files/sanoxovosotopefuseg.pdf
    • http://kftchem.com/upload/files/tumutumupejemosegekamani.pdf
    • https://vnmmalta.com/userfiles/file/gututufapisofabufavup.pdf
    • http://vietsinphar.com/uploads/files/budovoriniwelizi.pdf
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/071cd1fbf0b5eb69dd500f2c14add7d3/zotuzuberonujegapeg.pdf
    • http://pro-group.ru/userfiles/files/12187907446.pdf
    • http://broadviewlibrary.org/uploaded_bvlib/file/99593426478.pdf
    • http://cameranichietsu.com/luutru/files/31192675964.pdf
    • http://thaifilmind.com/UserFiles/file/dusesokibekulerejok.pdf
    • http://innova-perila.ru/upload/files/84244090920.pdf
    • https://heatingboiler.ca/fck_upload/file/tatolozorumax.pdf
    • https://gadesign52.com/uploads/files/202109132023462096.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=8+ball+pool+apk+download+unlimited+coins+and+cash
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1b0.bin
46401e2855e0bfc8c1b82bd280caefec8df193fd19ebf9fc2f78deb93f42f1a6
pdf-font-stream PDF embedded font (sfnt) at offset 0xC1B0 11208 bytes
font_01_sfnt_off0000db8b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB8B 16792 bytes
font_02_sfnt_off0000f39d.bin
5fdf45e5d9c97527f22e3d4866a0cd5f92d116e4700a302c0188e0491de2dcf2
pdf-font-stream PDF embedded font (sfnt) at offset 0xF39D 17132 bytes