Malicious PDF — malware analysis report

Static analysis result for SHA-256 76ecbb91e8f23991…

MALICIOUS

PDF

76.9 KB Created: 2021-07-16 06:34:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3bbbb064dd2a5922be4dc18a34e6e717 SHA-1: 241682e91d0025084628a02bf93819407205b2c3 SHA-256: 76ecbb91e8f2399130bcd5b17f2d31aedbe405bf8f93a8165543ba4b39f9d34a
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS upload directories, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were extracted, the structure and URL patterns are consistent with a malicious document used for initial access.

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 https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/ip72up0dughhi70dghp97afa07/92751217170.pdf
    • http://cupta.org/userfiles/files/20210612070906.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b04b71de158---pezifixokipevowekija.pdf
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/895cb1e4161a4f9794cf18e8b661c964/dabatipebexedunobup.pdf
    • http://brenna-ski.pl/userfiles/file/91340997391.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/bgufi52pgl9m3q5read9p9pfuo/72687368815.pdf
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/028db6850dfaed6c77cfdfbf22b72970/69904839705.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/b5sme3fspaueg4so1qcnn0cr9e/83009442280.pdf
    • http://cisseo.net/userfiles/files/piwejizetilevilat.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/ef800931a9599c3020d8d971bc18cc35/napizadagulajekub.pdf
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/b6b50a25f89ea43540069f127a7c24cb/19800544321.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ae2e7d2ee41---nepolu.pdf
    • https://mirrorlink.com/public/files/files/paxipiw.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/v8145lj8ljvojr1iavuacner53/56082417245.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0d5b92a31e46a4f359ecdc993a4b189c/borakizupomesexes.pdf
    • https://doublehair.center/upload/ckfinder/files/zoziwerazoxaw.pdf
    • http://agiusfuneraldirectors.com/files/file/85427116919.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/05bdd63c0cd48c44335618637ddfefa0/kiditidutukisigotute.pdf
    • http://schodylux.pl/userfiles/file/22854034608.pdf
    • https://menlopark.com/wysiwygfiles/file/40413973893.pdf
    • https://abofahed.com/userfiles/file/gatekewuxulunilorepiras.pdf
    • http://pokemom2.com/uploads/files/74723656479.pdf
    • https://legend-chang.com/UserFiles/files/jawodegasebof.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=multivariable+calculus+7th+edition+solutions
    • 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_off0000cba8.bin
0a92e787d08986761b09da9baa745b3f9d5b5653dd3b391b4898c83064566cb1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCBA8 10816 bytes
font_01_sfnt_off0000e4a3.bin
b1fd218393f5281198ecaa87a9c8a31b72dcfef1ec35101bd678f679d8967790
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A3 16128 bytes
font_02_sfnt_off00010df9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DF9 16792 bytes