Malicious PDF — malware analysis report

Static analysis result for SHA-256 164e632381371c77…

MALICIOUS

PDF

105.3 KB Created: 2021-06-28 06:19:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f9654f8d4b27ffbd58f04b7eac983d65 SHA-1: db23ac2d0e52aacbc857e15e2404c9f0dc6255a0 SHA-256: 164e632381371c774c3dd26054c9df46ef15cf7f0465566b7c9d7d8bf5c6f350
156 Risk Score

Malware Insights

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

The sample was detected by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The PDF structure itself is also noted as potentially compromised, with duplicate object bodies.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dianacb.cz/userfiles/file/bidowevef.pdf
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160984b656d756---16278922204.pdf
    • http://skiflogistics.ru/userfiles/file/zofinumowezuze.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf3e0a828eb---1454456974.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16070ecb8c9be5---79190941480.pdf
    • https://nabijdefossa.nl/upload/files/gugubewokelale.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16082f56972e46---91287067054.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/ou25rq1mprsha51kodejinocnd/xipekewufisazakoxifo.pdf
    • http://hb1004.com/userData/board/file/wemaxitivizasupu.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160734308608c0---vobagutomone.pdf
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/39907829a157b2efcfabd1c01655bc4a/xabumam.pdf
    • https://isleo.com/i_photos/file/bojefagiwa.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/d56b838243cd73098760ace31ecb3be6/69571610438.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b4ca69b9bd2---wonutuvow.pdf
    • https://aawyx.com/sites/default/imageuser/file/zubotugebakixobivazipil.pdf
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/kcpkf9aj6vk8c48bsc4lcbn2t6/wujozevumafotozutufus.pdf
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/1q69bsb0eihtm414sj4voldpt2/34244069336.pdf
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/6c0c041a76312e719d50a25755ea2341/damozuniwamomiwomusuwat.pdf
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160946ae669a55---9079744657.pdf
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/fe4f040c3e7a8e7776a8b68c0cd99245/firapodekaligojimuwide.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160722f6a7b5b1---fitovon.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=adobo+chicken+moes
    • 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_off00013636.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13636 16792 bytes
font_01_sfnt_off00014e4d.bin
7387fa3d26350640eea21ec4a4d6f3cec93b5e253a363e7bf4a384bebec79eab
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E4D 10444 bytes
font_02_sfnt_off000165c1.bin
c7f28e2d06494e26cb114633ff9e8f9fe05d1e7dc9042baecd863a32fbb7d066
pdf-font-stream PDF embedded font (sfnt) at offset 0x165C1 19408 bytes