Malicious PDF — malware analysis report

Static analysis result for SHA-256 538ef2c1ccf8104a…

MALICIOUS

PDF

89.3 KB Created: 2021-09-06 12:08:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 41a2b1bf545b49a9ba4d931099669381 SHA-1: 352a01d77a4d9dfe21ff9b931374cfcaae013d70 SHA-256: 538ef2c1ccf8104ad04c3280b37ed62e909181d118256accf057f5517100600b
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous links pointing to compromised websites, indicating a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' suggests the document is structured to exploit search engine optimization or leverage compromised content management systems to host malicious content. No scripts were extracted, but the overall structure points to exploitation for client execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/9e8b58b911d669cae436ab963fc81711/sebuxilonolilotape.pdf
    • http://lhs75aa.org/clients/0/08/08eb77d093c5251d787cf05842b4a73c/File/97040447913.pdf
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091efd12e30e---gaxewa.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/b25a1f8a2441017897c469b3b0050f79/82719366476.pdf
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/a0cabd1ef158e94e58fe47f39f4adc48/xigopeviwadesovufasos.pdf
    • http://ih-consultant.com/ckfinder/userfiles/files/83111246978.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3ed5723c83---demipofive.pdf
    • http://wx-test.com/upload/ckimg/files/202109030654388486.pdf
    • http://studiorumeo.it/userfiles/files/37398073237.pdf
    • http://assessmentinsight.com/ckfinder/userfiles/files/rokitizasawiw.pdf
    • http://yjsyrj.com/userfiles/file/28756177859.pdf
    • http://fbhsclassof70.com/clients/f/f6/f6e65d48c6cf753e26882f86001d336b/File/22076772065.pdf
    • http://kengosushionlineorder.com/uploads/files/josemidimu.pdf
    • http://alfavit.tv/userfiles/file/zinezananawodujuf.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1ede30235---vixikevevamiwawiredaji.pdf
    • http://3wsystems.com/shipinc/userfiles/files/nojatiximudejezem.pdf
    • https://www.bistro-e.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072e4628d3ef---3719511695.pdf
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/0095141c71f397543ef2090373e6da1b/88114777121.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc5c10b204---jigeguwilupunetozawo.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ff44c756509---fibugesababumowodamozed.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/orqvqa1or06fb745muqr82u0es/86705238912.pdf
    • https://szabolcsipeter.com/userfiles/file/70792341559.pdf
    • http://northcity.rs/slike/files/zewifasukixomobifu.pdf
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/ihv9hm605rcj5c2d90v0h30bld/59649920678.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=dda+line+drawing+algorithm+pdf
    • 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_off0000f34c.bin
a1beab0036dea19f8cb65b0968d60b52a649a8c1e8b18a1dc0519fbcecd4729b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF34C 10864 bytes
font_01_sfnt_off00010bf6.bin
3313a952f6224626d3492853cf45dc8ff3665fe2c73bbd97f54f45eeab8043a6
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BF6 19680 bytes
font_02_sfnt_off00013f49.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F49 16792 bytes