Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b8f034d0a1d68fc…

MALICIOUS

PDF

108.7 KB Created: 2021-08-06 13:44:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa43a4fe1e91cf832b973f3ec602150d SHA-1: 23352f8b40d039c6e77b1fd08b7d1f580692e96a SHA-256: 1b8f034d0a1d68fcc3313f9ba1b34de0b025498951b1a5aea1bd495290ff3046
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm hosted on compromised CMS uploads. The presence of numerous links, some pointing to potentially malicious PDFs, suggests an attempt to distribute malware or conduct phishing. While no scripts were directly extracted, the PDF structure and link farm behavior are indicative of a malicious document designed to trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077d0560c052---27278053264.pdf
    • http://geotersrl.it/file/lasupitiritelogoripirur.pdf
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076342f18bc1---95716515272.pdf
    • http://apsons.eu/files/file/kojuti.pdf
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/8e8352ada56cbcbc8f93e40515e5ee5e/22813384889.pdf
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/porevukori.pdf
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/270abcfa02803dcb56a4750e49a0dc04/21084807067.pdf
    • http://volamtuyetthe.com/userfiles/file/2217357239.pdf
    • https://vayamcs.com/content_files/files/vozonodurex.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a515cd1dc4---35162244261.pdf
    • http://www.lnk-creation.fr/upload/file/kipevusupotajoro.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c27c9ea9332---91146323285.pdf
    • https://iva-vietnam.com/userfiles/file/26145734162.pdf
    • https://rijst.nu/userfiles/file/30493900418.pdf
    • https://vasutaszeneiskola.hu/ckfinder/userfiles/files/xifepibuvaxazovubepakuv.pdf
    • http://alexanderkanevskyartgallery.com/clientMedia/file/83636410513.pdf
    • http://thegioidahoacuong.com/uploads/image/files/83223514549.pdf
    • http://plafondchauffant.fr//img/user/file/kujajuwosewi.pdf
    • http://amsasecretariat.fr/userfiles/file/nokuditufoketejug.pdf
    • https://xn--interpeas-r6a.es/upload/files/wazemag.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d628d46a9---35028336227.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c47cbe3b653---30469007719.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=bully+anniversary+edition+mod+apk+revdl
    • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off00012434.bin
65888dcf68d5b93e3b461f4f0dda69f6e4dac62425c8b0c2698ae57ea44de44a
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12434 26792 bytes
font_00_sfnt_off00010aaa.bin
a35e24c0ec656ff7b0271621da2c9b07f28f5d7d505650803a754720ee45b075
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AAA 10976 bytes
font_02_sfnt_off000154e1.bin
b2aec555eda79c0eef5446019771e8da873a29dcf230a88a61c5f14bdf811faf
pdf-font-stream PDF embedded font (sfnt) at offset 0x154E1 18660 bytes
font_03_sfnt_off000183a1.bin
2d59b2b1bb9a6f9bbf889029c1db5c2207fa4dbd30617e885d593f86b64e3e7b
pdf-font-stream PDF embedded font (sfnt) at offset 0x183A1 1704 bytes
font_04_sfnt_off00018ba8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18BA8 16792 bytes