Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfa5cb7f82031fac…

MALICIOUS

PDF

82.9 KB Created: 2021-08-23 17:59:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c31db0d9a86f8f24ee1fe21a0f1b8c77 SHA-1: 4a7ce572fa2dd6831b411220f1e65923f4e18717 SHA-256: cfa5cb7f82031fac69b78f16f919bebb784384817d1f57cce289fc786538435f
184 Risk Score

Malware Insights

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

The sample is a malicious PDF detected by ClamAV and ML classifiers, containing embedded JavaScript. This script likely facilitates the execution of malicious code or redirects the user to external URLs, as indicated by the numerous PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The presence of external links, including one pointing to a raw IP address, suggests an attempt to download further payloads or conduct phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://beijingxinzhi.com/userfiles/file/20210619084859_696624031.pdf
    • http://s2ipower.com/survey/userfiles/files/sepepaduzuredaliga.pdf
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/b5j687k4m7svkefs8ru62r843p/74762186115.pdf
    • http://saydersan.com/firma/files/gekelu.pdf
    • https://mtestbd.com/assets/uploads/files/faligewatuwojur.pdf
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/d29672665d3cc8155feae95441c9a00d/lapetigorotiluwivel.pdf
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/dd19eee285fac2323561eb83d6a84dee/mezesedefumuwofene.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16076f263f0440---kegutuzizozakepamajop.pdf
    • https://jjcfurnituremaker.com/userfiles/files/76208501256.pdf
    • http://140.121.180.103/ckfinder/userfiles/files/xonugekijul.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/9cd2bd9ee00f35e3e4495f3a00ed0dc6/sodukoreduvepivinuwadikuz.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/b0e691e0fd6cb20663f28649e0ba5f92/75526625535.pdf
    • https://hyosungulf.com/uploads/file/vokinegupofovozisad.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/e4f9e58e4af8fd56acfe45315f1146c5/37760703280.pdf
    • http://classiccar-jp.com/js/upload/files/zurawabez.pdf
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/285157172e5a4e16a19653167fb93b91/sisetaxazupesebim.pdf
    • http://amphorabeautyclub.com/campannas/file/14640070678.pdf
    • https://ises.ca/phpsites/vertical_living/uploads/file/51718475745.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160aba11e523e1---14561929406.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609842e067a27---18189190081.pdf
    • http://chemonova.com/FCKeditor/file/78907806330.pdf
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a8677d03385---9404876713.pdf
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/77ed533c115683186d5a63345209560d/82015042456.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=to+the+devil+a+daughter+1976
    • 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_off0000df79.bin
b27ab1003ef4f212730678aa4ddb58673c219f0ef5a51b084c291270684cdc9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF79 10820 bytes
font_01_sfnt_off0000f86f.bin
3677eeb90a21705c357a7068a09a03079227d5417bcacbed8165b46a8c282ddc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF86F 16892 bytes
font_02_sfnt_off0001248c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1248C 16792 bytes