Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb4afc4423675976…

MALICIOUS

PDF

78.5 KB Created: 2021-09-21 17:54:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3a27637dcabb7745d62704195c5a14e9 SHA-1: bb58a1572d19a1d612bc231eaa3e4271825619a2 SHA-256: fb4afc442367597660fa7b6269281f4a3104159fbe7fbd2e662f7d048bdee72f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised CMS uploads or disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://sjhrz.com/images/upload/File/ramega.pdf In PDF document text
    • https://mai-avto.ru/upload_files/file/89845178931.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161426a9892001---39811163566.pdfIn PDF document text
    • https://riolisboa.com/images/ul_files/file/mUhAOiCepQFy.pdfIn PDF document text
    • http://inica.org/files/file///lojusefimuzipepejaguva.pdfIn PDF document text
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/kevogidijezus.pdfIn PDF document text
    • http://bassonconsulting.mc/userfiles/file/xagidazuledunutikuvupezu.pdfIn PDF document text
    • http://hsound.ro/images/custom/file/xewofajazutejoliguledora.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/joxovalutagekitewivirupo.pdfIn PDF document text
    • http://dgkno.cn/upload/50673710703.pdfIn PDF document text
    • https://sentinels.ro/userfiles/file/49115060673.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/41612804480.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/genivumifidetuviwiju.pdfIn PDF document text
    • https://futurefacesnyc.com/uploads/file/vigugovag.pdfIn PDF document text
    • https://xn--23-6kci4asohe8k.xn--p1ai/userfiles/file/55914458165.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba9e938776.pdfIn PDF document text
    • http://checopharma.com/upload/files/mubakepunafoliji.pdfIn PDF document text
    • http://cermak-expo.cz/data/files/file/48654114349.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/wufivut.pdfIn PDF document text
    • https://rzfmuhasebe.com/userfiles/file/kizonutuvojixola.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf1810e964---24874105293.pdfIn PDF document text
    • https://hopclickhospitality.com/scgtest/team-explore/uploads/files/wedipomemuzivemazu.pdfIn PDF document text
    • https://yuvasarkar.org/userfiles/file/16174833256.pdfIn PDF document text
    • http://smartraoptics.com/fck_filemanager_upload/file/zizajitiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=display+clock+on+home+screen+androidPDF 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_off0000cf67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF67 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e77e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE77E 10888 bytes
SHA-256: f6ca90f1b245de048ace91da8b326e082b52da489b16bc1a8114032912ecf2f9
font_02_sfnt_off00010070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10070 16988 bytes
SHA-256: 576bbdb31ac9d6fd6f84e600125a3447d8e509a9587008d151eeaf04be8aea48