Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5543daf071912f3…

MALICIOUS

PDF

71.4 KB Created: 2021-09-27 06:44:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: df2873141acecbeac20cf60c4e27bf47 SHA-1: f96d8ba68a59f143390edf9afbf805903430398b SHA-256: a5543daf071912f3217d90ee5490165ad68dd2565f9952ab3288e2855461dd52
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external URLs, many hosted on compromised or disposable domains, suggesting a link farm designed to redirect users to malicious sites. The ClamAV detection and ML classifier further support its malicious nature, likely as a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • 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 https://allytemp.ru/uplcv?utm_term=transfer+music+from+pc+to+phone
    • http://plusk-car.com/js/upload/files/26626000852.pdf
    • http://yuanhebiotech.com/upload/files/46267420721.pdf
    • https://intekcanada.com/ckfinder/userfiles/files/sosibo.pdf
    • http://miyisz.com/mingyi/images/userfiles/file/62011322058.pdf
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614002999a34f---lazokawidirakutafebur.pdf
    • http://faizleathergloves.com/userfiles/files/linik.pdf
    • https://fanaf.com/article_ressources/file/kapubevin.pdf
    • http://jianianhuayule.a9188.com/upload_files/art_files/files/20210904_041352.pdf
    • http://fantasymusic.it/userfiles/files/voken.pdf
    • https://bataretak.com/img/files/file/81002641962.pdf
    • http://etpatatietpatata.com/userfiles/files/76082976111.pdf
    • http://sithome.com/upfiles/file/20210914140855.pdf
    • https://pracowniatechart.pl/fckpliki/file/20848526222.pdf
    • https://netcsemege.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/8805008101.pdf
    • http://pro-group.ru/userfiles/file/36715351984.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614d150d7a4f6---90001630698.pdf
    • http://j1medical.com/uploaded/file/42161295211.pdf
    • http://3sdent.com/upload/files/bifofamuzesu.pdf
    • http://jfhcoaching.com/userfiles/files/23630406824.pdf
    • http://firmykominkowe.pl/Obrazki/edytor/file/8583988280.pdf
    • https://slezanie.eu/userfiles/file/wukozotebanek.pdf
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/1e041bb3afa841d34da789a01c324510/vebaretijagoromore.pdf
    • http://ranahytta.com/ckfinder/userfiles/files/71246086106.pdf
    • http://bukharaalpharetta.com/sites/default/files/file/98796764044.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_off0000b4ac.bin
6c86964950ab271e63e239ac439c8de24b55e55cc37eb224460ceb1bf0dd71d8
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4AC 16708 bytes
font_01_sfnt_off0000df2c.bin
44398fc08d2fee325027d64e9920bd1d5bb00ba7f91ddff1ca3192621844a4ab
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF2C 10760 bytes
font_02_sfnt_off0000f7bd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BD 16792 bytes