Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4153683c80dc3d3…

MALICIOUS

PDF

74.6 KB Created: 2021-07-06 18:56:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0c3db7d9c08c884ef9ea46461ae5f654 SHA-1: 96b6320d36c68395cff64a26809735ee2b9fd3ba SHA-256: b4153683c80dc3d3c5f8071dc6e6bf77862de208d1b35047b0f7605be6844e6a
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on domains identified as disposable or potentially compromised CMS uploads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://beliangka.com/contents//files/pekel.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086daf0922c2---perolitutitin.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/2t0ig7ff21tdb65dklkmies414/52880881746.pdf
    • https://viratrip.com/basefile/travelasreviracom/files/ritaxuruzipuw.pdf
    • https://alatheir.com/atheirwsfiles/file/kemovenoludagiman.pdf
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/mikezasegepexiriw.pdf
    • http://starlightcelebrates.com/clients/4/43/43e9139217482d7666ce300faf566241/File/60860668746.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7724d1e24---88570566122.pdf
    • http://shlawllc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/92404957972.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f944127ae---kodulotupudoxaviruzipive.pdf
    • http://shuswapladystriders.ca/userfiles/file/tobosowuzafefulukorurimo.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a24a57837cf---17591190431.pdf
    • http://mwflower.com/upimagesfile///65735635991.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e2ba362d29---poretexev.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//20802482898.pdf
    • http://areawifi.com/DESARROLLO/userfiles/files/lagagofo.pdf
    • https://unosms.us/userfiles/file/davadadika.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e2518204a---kakamoruzerejifiwabudoka.pdf
    • http://surrattsville69.com/clients/8/81/8122276c22396d7fa0996010cc369f50/File/49074462395.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16097c6f487516---98342580246.pdf
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/8103755deeca8b2832d97503501cbca9/88670288261.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1ac4993789---gumafagujaferejerora.pdf
    • http://archiprojektai.lt/app/webroot/uploads/userfiles/files/lepuvekusuferigojolamiz.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae72ba85064---37552136683.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=physics+principles+and+problems+chapter+21+study+guide+answers
    • 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_off0000bfdb.bin
c4c42b1107adf810a0ba5cd1a77ebd3af13f15b586a532ab22469acfda7f0a4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFDB 16152 bytes
font_01_sfnt_off0000e956.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE956 16792 bytes
font_02_sfnt_off0001016d.bin
8dd11229402500941d74dda7a85d8bb48a678339428b47099bf42424448290c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x1016D 11576 bytes