Malicious PDF — malware analysis report

Static analysis result for SHA-256 c73c3f1dde024579…

MALICIOUS

PDF

86.3 KB Created: 2021-07-28 08:35:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6114a193c6fce1acfa20dde707b4d5b9 SHA-1: 4e09f09aec95a6287fd02e22d1878bbd4c714b28 SHA-256: c73c3f1dde02457933e3b82c09706d371add182e72c231a12ef08314c6d28e62
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous unknown PDF files hosted on compromised websites, suggesting a phishing or malware distribution scheme. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c154854fd4e---6531269280.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/d6g4uev8if5na7a77m243fked3/soxutox.pdf
    • http://goref.ru/files/file/rubex.pdf
    • http://mfahk.com/upload/files/73064415716.pdf
    • http://kozelskadm.ru/files/uploads/files/poganiguneponazutowif.pdf
    • http://diversecityuk.com/userfiles/file/59986612747.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6e1194d1a0---36101220302.pdf
    • http://xedaphcm.com/luutru/files/melavizav.pdf
    • https://sanruouvang.net/images/uploaded/file/10277033911.pdf
    • https://adreshosting.com/calisma2/files/uploads/zazoje.pdf
    • http://studiogallerani.it/userfiles/files/fuxuzadu.pdf
    • http://younewstoday.com/task/userimages/file/punofudimimoxefuw.pdf
    • http://alliance-ltd.com/userfiles/segazulewugafivife.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608abb7cc3bf1---6867095311.pdf
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/26fc6910fdec8a4d4cd89a2320e44fa7/giwapirasujitibo.pdf
    • http://mid-europe-ex.com/images/blog//file/dapewumezodamumebofeziz.pdf
    • http://quick-thailand.com/images/uploads/file/7034320369.pdf
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608123e536097---41585903382.pdf
    • https://hanahana.vn/media/ftp/file/61327560120.pdf
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/193e647ee902bd36c895dc3d47564672/68965765016.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb506381a6d---bujogubaj.pdf
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc23dd308f---91535831478.pdf
    • http://ebiocell.com/uploadfile/file///2021072804052529.pdf
    • http://aucoindeshalles.com/menu/file/56274543053.pdf
    • http://master-sign.ru/ckfinder/userfiles/files/momisapux.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=plantilla+a4+escribir+recto+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_off0000e5e2.bin
d3ccf223c9b6e149d0c7c454064dde7ec88b718a57f832d98ab28fc0bd7d0511
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E2 10832 bytes
font_01_sfnt_off0000fecf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFECF 16792 bytes
font_02_sfnt_off000116e1.bin
1206edcdded21bf701c7ca41bb17caeb4cca2aaf82a561d08bf71cc8cc605c42
pdf-font-stream PDF embedded font (sfnt) at offset 0x116E1 20188 bytes