Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff8b9467bf0b1da5…

MALICIOUS

PDF

79.7 KB Created: 2021-09-08 23:10:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 63b431c5b7c45ba9b114f125de83cf33 SHA-1: 73a02c0e6681a1008f64d4d201b04973010c882c SHA-256: ff8b9467bf0b1da5ee92f4dc9911b96c687e34dcbab9fb68fd95cddcdf9a1f77
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised or disposable hosting sites, such as 'synerhu.ru' and 'allineers.netlovestories.com'. The presence of external URIs and link farm characteristics strongly suggests a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6200

Heuristics 6

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://synerhu.ru/uplcv?utm_term=office+365+work+login PDF link annotation
    • http://allineers.netlovestories.com/upload/files/venafonelaluvobirubikap.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161306c1898a13---88341994247.pdfIn PDF document text
    • http://myslizdrave.com/soubory/15692369504.pdfIn PDF document text
    • https://www.xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/xaberorevo.pdfIn PDF document text
    • https://osakaav.com/userfiles/files/37039451400.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/refoxes.pdfIn PDF document text
    • http://slovbau.sk/test/userfiles/file/nazamosoza.pdfIn PDF document text
    • http://buffagiuseppeinfissi.com/userfiles/files/dobojomufev.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/suwunovefefimatemer.pdfIn PDF document text
    • http://jingmingtai.com/filespath/files/20210908152123.pdfIn PDF document text
    • http://xetaihyundai.net/upload/files/95285289259.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/berapedofukodalapugo.pdfIn PDF document text
    • https://tennis94.fr/img/pics/files/49849146263.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/watikud.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/dfb8e69ee17415893bd590cbec00685c/goziridofolefevoti.pdfIn PDF document text
    • http://rapabzenec.cz/obrazky/files/5083483699.pdfIn PDF document text
    • https://gesema.com/UserFiles/file/pemixa.pdfIn PDF document text
    • http://moscow-vernisage.com/files/files/61156907727.pdfIn PDF document text
    • http://anticacarsulaeborzoi.eu/userfiles/files/sinariwizapujogadebiwisim.pdfIn PDF document text
    • http://samtekelektrik.com/files/83563322002.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/6f2f2da8bad62764e2305067279edf6e/kaxabikorabigiwuvilafonol.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16135c721f2d62---wulekakejakiruseboke.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021090513295073499.pdfIn PDF document text
    • https://luatsubienhoa.com/upload/ck/files/39441115110.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/wepogugituwakuvivil.pdfIn 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_off0000debf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBF 10760 bytes
SHA-256: dba035dc4e3a5bf0ebea8a6f77edf6fe0509c852d1996f07dcfbddda68cb1de8
font_01_sfnt_off0000f7b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010fc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FC9 18328 bytes
SHA-256: efa21d70130cf46fde0422600fe16991439bb9c8934b99b74902cf876c2a4ac4