Malicious PDF — malware analysis report

Static analysis result for SHA-256 a70b39d80838f9a9…

MALICIOUS

PDF

76.0 KB Created: 2021-09-09 12:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 86d34b0ab947f9326d92bc2f0414d1a1 SHA-1: c681389cb71cd5efde8a5fb11109e1468e8ed6f5 SHA-256: a70b39d80838f9a9d338ed662c2a4aab4009ed77531ee6b8c69f017add8c1d2d
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS upload storage. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the presence of numerous external links suggests it is designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161329e32949e5---xitona.pdf
    • http://biosurfest.com/userfiles/files/11503045139.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/0f4e54362d5d0f6aebee2ff0bff7617e/lulago.pdf
    • http://restokrat.info/userfiles/file/5425430954.pdf
    • http://phunggia.biz/userfiles/file/xudufigamidevasoludovo.pdf
    • http://peggylittlelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pudisijote.pdf
    • https://danielfelber.ch/userfiles/file/basisunemilufewete.pdf
    • http://gamecoast.by/uploads/files/64055537173.pdf
    • http://asfalon.com/__files/file/tibotatonejo.pdf
    • http://baheth24cars.com/ckfinder/userfiles/files/rubejax.pdf
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/75986890981.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-9-8/20210908005339649553.pdf
    • http://kayapalinakliyat.net/file/90940254314.pdf
    • http://fpempresa.cen.es/userfiles/files/93392513627.pdf
    • https://relans-nn.ru/images/docs/file/32760994515.pdf
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/82946184305.pdf
    • http://hwayinn.com/image/files/20210905_204917.pdf
    • https://nbtele.com/en/cache/fck_files/file/25847568174.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132683e641f0---bixedidik.pdf
    • http://moje-stranky.eu/userfiles/file/63223601269.pdf
    • http://damnoen.com/ckfinder/pho/files/miwifagemorifitizoxuwut.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=paranoid+android+drum
    • 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_off0000c6af.bin
a8dcac20a4b8dec922a74134f12f2e4185e63aff72cc96ca288a8f8812ca6f9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6AF 10064 bytes
font_01_sfnt_off0000dcec.bin
d2fa854af4b26a71a1ee4a2fec698656c8822ac597ae33fa85c5cf738473f917
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEC 17516 bytes
font_02_sfnt_off00010ac2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC2 16792 bytes