Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa7adb4c651a4566…

MALICIOUS

PDF

68.0 KB Created: 2021-09-29 00:57:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 38a7717d0f3c6785ccf4c62573a02432 SHA-1: 097ad976253f78bcbb4b99da01992b7e8d664d17 SHA-256: aa7adb4c651a456627e0d48592f35e36c38939c3fa3b13f8aeb007db56abe831
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to various domains, many of which are identified as link farms on potentially compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://pixomot.ru/uplcv?utm_term=apk+nicco+app PDF link annotation
    • http://saeronbio.com/userData/board/file/96747609434.pdfIn PDF document text
    • https://alternativi.brtim.com/uploads/wysiwyg/files/dugimajiranofifizaladabub.pdfIn PDF document text
    • http://we2meeting.com/ckfinder/userfiles/publics/files/jevuzifusisup.pdfIn PDF document text
    • http://www.bluewhaleline.com/image/upload/File/52969873867.pdfIn PDF document text
    • http://logicparcel.net/uploadsEditorfile/zixibu.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/p1k1h0qmqn0cnc7ci14keg41vk/wavomatizej.pdfIn PDF document text
    • http://culfordequestriancentre.org/UserFiles/file/zosotepudiloje.pdfIn PDF document text
    • http://majstrissmt.eu/www-data/file/semidajuguxu.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/48324850238.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/gawasekadezefirolep.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ede8de15b---kilezufa.pdfIn PDF document text
    • https://vannordenvastgoed.nl/userfiles/file/42173618606.pdfIn PDF document text
    • http://numismatika-nbkpdy.cz/userfiles/file/lajozejeguvet.pdfIn PDF document text
    • http://xecuoihuyhoang.com/uploads/userfiles/file/63892910945.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138ef0f3c18d---pesarunukategaba.pdfIn PDF document text
    • https://henseltech.cz/userfiles/file/muzifomasig.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140766541a08---jevepugotixizifova.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/62877227026.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/60732332415.pdfIn PDF document text
    • http://www.lbtfilm.com/uploads/files/witiwedexamu.pdfIn PDF document text
    • https://www.multilandtours.com/assets/ckfinder/userfiles/files/tuzeguga.pdfIn PDF document text
    • http://moneymaker-gold.de/files/kivasokapaneb.pdfIn PDF document text
    • http://getrade.net/uploadfiles/file/26869581815.pdfIn PDF document text
    • http://mibenjamin.com/userfiles/file/53995291979.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/70701817033.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_off0000b014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB014 9896 bytes
SHA-256: c0be95174d033d919bfad08c6423defa0e895edac3dcc4d6e165d8a11237c448
font_01_sfnt_off0000c609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC609 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000de1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1B 14676 bytes
SHA-256: c862457cc27bafa803a152abb664b9faaa4120128f79d78e224cd82930002309