Malicious PDF — malware analysis report

Static analysis result for SHA-256 aecba7da4894fb05…

MALICIOUS

PDF

70.6 KB Created: 2021-09-22 16:17:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2d62ba1286f2f79c45f448c5eaf9d244 SHA-1: 37cd80c6cac2b549ee58f21305dfe26dfd40d065 SHA-256: aecba7da4894fb05a36eba5c2f0c7e85305f2f5c8223a4e41d3b0c81227bba50
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to link farms on disposable or compromised hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to redirect users to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • 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://medvor.ru/uplcv?utm_term=zarchiver+apk+for+pc PDF link annotation
    • https://accuratesearch.com/userfiles/file/32929512032.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/94122509859.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210909_74CB4E5F76D92C0C.pdfIn PDF document text
    • http://www.sunriseacademy.in/ckfinder/userfiles/files/toxobisu.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/fomokebetuvidinu.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210919192813.pdfIn PDF document text
    • http://zeguvietnam.com/uploads/ckfinder/files/jofubuvakipamit.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9c197fefe---40681213966.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161442f5a566e8---lixudagenesereboj.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/57408980892.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16135712c70acd---92863461660.pdfIn PDF document text
    • http://nanopena.cz/upload/file/35527435528.pdfIn PDF document text
    • https://copperscraphandlers.com/ckfinder/userfiles/files/kudokelidijokewi.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614221350c7f1---kamugelukejofulakaraf.pdfIn PDF document text
    • http://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/nozetamumirupinobunu.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/kigut.pdfIn PDF document text
    • http://www.florentmaussion.net/userfiles/File/fuzoginosi.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210914150110.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/gotomixod.pdfIn PDF document text
    • http://idcla.net/upload/files/gitexawozezuluketobilexu.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2FB 16584 bytes
SHA-256: fd7245577f80d9e9deb8d0ebff7b8a429e99d2dcb5379351a9c8cfc62667a966
font_01_sfnt_off0000dde5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDE5 10284 bytes
SHA-256: 570fc0e090d93e047cf1852afb81da4120c88b5061f34eb02d4f740cab9316a0
font_02_sfnt_off0000f53a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1