Malicious PDF — malware analysis report

Static analysis result for SHA-256 4088ba71a23572aa…

MALICIOUS

PDF

90.8 KB Created: 2021-07-04 18:17:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 57e24eb4f52b04766c4752e803129133 SHA-1: ecdc7f02a146408dbc92be3c30b7e031802be6a9 SHA-256: 4088ba71a23572aa424f4257775294b61803b3988a3aa9006d97196b9eaad9e4
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of these links and the detection scores strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 6

  • 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.
  • 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.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e6c82cb41---29281637274.pdf
    • http://www.biotanika.pl/upload/file/20228073567.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a35520971---gisipadara.pdf
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/l73va0po4cufnrqukcpe88nntu/zilasomeno.pdf
    • https://acryl-bg.com/userfiles/file/35257680527.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b5d91921b99---ranati.pdf
    • http://zatexpress.com//upload/userfiles/files/worutijanurugijigegasepi.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a76e9ca06---90859797077.pdf
    • http://groupkaishan.com/d/files/29622315921.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/9152f4b0830db562554563e03231992d/resekogumugukegizivepote.pdf
    • http://footstepfloor.com/upfiles/files/97405460724.pdf
    • http://polimak.pl/userfiles/file/30870688397.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/gbach7q7fdrldv8eum64odd167/navanolitovonofidofodo.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076d3f1a2110---90601674892.pdf
    • http://epmachine.ru/d/files/lekulowinezojep.pdf
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/616998c230377a3f535d106f9437e574/beputasokuduwibof.pdf
    • https://salvatoredivilio.it/userfiles/file/bowog.pdf
    • http://deltools.com/userfiles/file/bezisunubutanepuginidadul.pdf
    • http://www.mywil.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160a4f69e5f74a---pisudolavufupatiburuluji.pdf
    • http://bezpiecznamlodosc.org/files/file/18272567645.pdf
    • http://goref.ru/files/file/19458160997.pdf
    • http://saltokisport.com/uploads/files/dixutulipegivinedefakigu.pdf
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd04056cee---durubepaxigabeponuzamis.pdf
    • https://cabsfromheathrow.com/userfiles/file/wusoxuret.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=belly+tightening+34+weeks+pregnant
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/1ef693d5757318a98c5749a07d3a1455/98266333069.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_off0001016a.bin
6ad4d37ec63e5c0762dba6a2bdc8c7c3100e595ed617a3e1a71dc523bcaa3778
pdf-font-stream PDF embedded font (sfnt) at offset 0x1016A 16496 bytes
font_01_sfnt_off00012bfc.bin
529191e229621c03749ddbe02a458dca40e2cc3a579e34951fa3e8b415650a65
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BFC 11004 bytes
font_02_sfnt_off000145ae.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x145AE 16792 bytes