Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1562640bfa0340e…

MALICIOUS

PDF

80.4 KB Created: 2021-09-19 12:51:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3779091e9b410eca1cc85a3423e71378 SHA-1: bb7c0bae1012fa65f6551133c9630c32a5e8747c SHA-256: c1562640bfa0340e608839fd57d64622048945d14da20e7d25ce4213a4cc2bb5
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://philabc.ru/uplcv?utm_term=face+call+app+download
    • http://cx-gl.hu/images/files/1641550393.pdf
    • http://nwhouse.ru/uploads/file/mitopisaguzotodixixuvav.pdf
    • https://hsiaoying.com/userfiles/file/dituzon.pdf
    • https://aiwatopup.com/ckfinder/userfiles/files/nodetexogezaxaralito.pdf
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161447c66973a2---66403571642.pdf
    • http://transcash.com/ci/userfiles/files/24325680480.pdf
    • http://lev-steklo.ru/userfiles/file/nezapinevalabad.pdf
    • https://askisan.com/upload/ckfinder/files/88190558464.pdf
    • https://baxsporthorses.com/userfiles/file/zojisutokegujuvexa.pdf
    • https://aurorabersinar2.com/contents/files/43141980815.pdf
    • http://jayeonrak.com/upfile_editor/2021/files/nilomowemumivojaxitese.pdf
    • http://datcat.vn/2018/file/zipanig.pdf
    • https://justforjetscatering.com/userfiles/image/files/15420860883.pdf
    • https://vroa.pl/chplusfiles/file/12090037072.pdf
    • http://ambulatorioveterinariocamali.com/userfiles/files/61524558258.pdf
    • http://liga-stf.ru/i/upload/files/28602738053.pdf
    • https://ajambary.com/userfiles/file/47796458041.pdf
    • https://democv.associasuite.com/imagenes/contenidos/files/dosalovevasepewowefezi.pdf
    • http://fsgzb.com/upfolder/e/files/20210917134737.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613b65827b96d---rilufujevufif.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/349efa95279a31e7020e490c0c9944d7/vimutesibekasudolugiputu.pdf
    • https://triptoboloyfoundation.org/editorsfiles/files/vuxilojim.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef40f60ab6---10603244274.pdf
    • https://molecult.metallo-tests.ch/sites/web/upload/files/foseges.pdf
    • 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_off0000d6e7.bin
79d7ec13a7492b1bd6929144f306fb65fad8cc0f6f60a3054fd0820f62596210
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E7 10112 bytes
font_01_sfnt_off0000ed9a.bin
98a5b8479a453d9454744fb5b648dc3f1d675580a72f487093bd02034c48dc6c
pdf-font-stream PDF embedded font (sfnt) at offset 0xED9A 17936 bytes
font_02_sfnt_off00011c3d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C3D 16792 bytes